No fossils are as impressive as the ones found in that valley.
→ The ........................ have been found in that valley
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.
What geologists call the Basin and Range Province in the United States roughly coincides in its northern portions with the geographic province known as the Great Basin. The Great Basin is surrounded on the west by the Sierra Nevada and on the east by the Rocky Mountains; it has no outlet to the sea. The prevailing winds in the Great Basin are from the west. Warm, moist air from the Pacific Ocean is forced upward as it crosses the Sierra Nevada. At the higher altitudes it cools and the moisture it carries is precipitated as rain or snow on the western slopes of the mountains. That which reaches the Basin is air wrung dry of moisture. What little water falls there as rain or snow, mostly in the winter months, evaporates on the broad, flat desert floors. It is, therefore, an environment in which organism battle for survival. Along the rare watercourses, cottonwoods and willows eke out a sparse existence. In the upland ranges, pinion pines and junipers struggle to hold their own.
But the Great Basin has not always been so arid. Many of its dry, closed depressions were once filled with water. Owens Valley, Panamint Valley, and Death Valley were once a string of interconnected lakes. The two largest of the ancient lakes of the Great Britain were Lake Lahontan and Lake Bonneville. The Great Salt Lake is all that remains of the latter, and Pyramid Lake is one of the last briny remnants of the former.
There seem to have been several periods within the last tens of thousands of years when water accumulated in these basins. The rise and fall of the lakes were undoubtedly linked to the advances and retreats of the great ice sheets that covered much of the northern part of the North American continent during those times. Climatic changes during the Ice Ages sometimes brought cooler, wetter weather to mid-latitude deserts worldwide, including those of the Great Basin. The broken valleys of the Great Basin provided ready receptacles for this moisture.
Why does the author mention Owens Valley, Panamint Valley, and Death Valley in the second paragraph?
A. To give examples of depressions that once contained water.
B. To explain their geographical formation.
C. To compare the characteristics of the valleys with the characteristics of the lakes.
D. To explain what the Great Britain is like today.
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.
The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.
Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.
Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significant greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.
However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperature were too high and particles of matter were moving around much too rapidly. It was only after the one-minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased.
Most of the helium in the universe was formed ______
A. during the first minute of the universe's existence
B. in a very short time
C. in interstellar space
D. before most of the hydrogen
Kiến thức: Đọc hiểu
Giải thích:
Hầu hết helium trong vũ trụ được hình thành ______
A. trong phút đầu tiên của sự tồn tại của vũ trụ B. trong một thời gian rất ngắn
C. trong không gian giữa các vì sao D. trước phần lớn hydro
Thông tin: However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperature were too high and particles of matter were moving around much too rapidly. It was only after the one-minute point that helium could exist.
Tạm dịch: Tuy nhiên, khi vũ trụ hình thành chưa đầy một phút, Heli đã không thể tồn tại. Các tính toán cho thấy rằng trước khi nhiệt độ thời gian này là quá cao và các hạt của vật chất đã được di chuyển xung quanh nhiều quá nhanh. Chỉ sau mốc một phút Heli mới thể tồn tại.
Chọn B
Dịch bài đọc:
Các yếu tố ngoài Hydro và Heli tồn tại với số lượng nhỏ đến nỗi chính xác khi nói rằng theo trọng lượng, vũ trụ có phần hơn 25 phần trăm heli tính và phần nào ít hơn 75 phần trăm Hydro.
Các nhà thiên văn đã đo sự dư thừa của Heli khắp thiên hà của chúng ta và các thiên hà khác. Heli đã được tìm thấy trong những ngôi sao tồn tại đã lâu, ở những ngôi sao tương đối mới, trong khí giữa các vì sao, và trong các đối tượng ở xa gọi là chuẩn tinh. Hạt nhân helium cũng đã được tìm thấy là thành phần của các tia vũ trụ chiếu xuống Trái đất (tia vũ trụ không phải là thực sự là một dạng bức xạ, chúng gồm các hạt của nhiều loại khác nhau di chuyển nhanh chóng). Nó dường như không làm khác biệt đi nhiều nơi Heli được tìm thấy. Sự phong phú tương đối của nó dường như không bao giờ thay đổi nhiều. Ở một số nơi, có thể có nhiều hơn một chút; ở những nơi khác, một chút ít, nhưng tỷ lệ Heli trên các hạt nhân Hydro luôn luôn vẫn như nhau.
Helium được tạo ra trong các ngôi sao. Trong thực tế, phản ứng hạt nhân mà chuyển đổi Hydro thành Heli đảm nhiệm hầu hết năng lượng mà các ngôi sao tạo ra. Tuy nhiên, lượng Heli có thể đã được sản xuất theo cách này có thể được tính toán, và hóa ra là không có nhiều hơn một vài phần trăm. Vũ trụ đã không tồn tại đủ lâu để con số này là lớn hơn đáng kể. Do đó, nếu vũ trụ là có phần hơn 25 % Heli bây giờ, thì nó phải có được khoảng 25% Heli tại một thời điểm gần lúc nó hình thành.
Tuy nhiên, khi vũ trụ hình thành chưa đầy một phút, Heli đã không thể tồn tại. Các tính toán cho thấy rằng trước khi nhiệt độ thời gian này là quá cao và các hạt của vật chất đã được di chuyển xung quanh nhiều quá nhanh. Chỉ sau mốc một phút Heli mới thể tồn tại. Đến thời điểm này, vũ trụ đã quá nguội đến nỗi Nơtron và Proton có thể kết hợp vào nhau. Nhưng phản ứng hạt nhân dẫn đến sự hình thành của Heli đã hoàn thiện trong một thời gian tương đối ngắn. Sau khi vũ trụ được hình thành vài phút, việc tạo ra Heli đã không còn hiệu quả.
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.
The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.
Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.
Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significant greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.
However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperature were too high and particles of matter were moving around much too rapidly. It was only after the one-minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased.
The word "constituents" is closest in meaning to _____
A. causes
B. components
C. relatives
D. targets
Kiến thức: Đọc hiểu, từ vựng
Giải thích:
constituent (n): thành phần
cause (n): nguyên nhân component (n): thành phần
relative (n): họ hàng target (n): mục tiêu
=> constituent = component
Thông tin: Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth
Tạm dịch: Hạt nhân helium cũng đã được tìm thấy là thành phần của các tia vũ trụ chiếu xuống Trái đất
Chọn B
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.
The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.
Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.
Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significant greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.
However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperature were too high and particles of matter were moving around much too rapidly. It was only after the one-minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased.
The word "vary" is closest in meaning to
A. include
B. mean
C. stretch
D. change
Kiến thức: Đọc hiểu, từ vựng
Giải thích:
vary (v): thay đổi
include (v): bao gồm mean (v): có nghĩa là
stretch (v): căng ra change (v): thay đổi
=> vary = change
Thông tin: Its relative abundance never seems to vary much.
Tạm dịch: Sự phong phú tương đối của nó dường như không bao giờ thay đổi nhiều.
Chọn D
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.
The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.
Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.
Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significant greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.
However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperature were too high and particles of matter were moving around much too rapidly. It was only after the one-minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased.
The word "they" refers to _____
A. particles
B. cosmic rays
C. constituents
D. radiation
Kiến thức: Đọc hiểu
Giải thích:
Từ "they" dùng để chỉ _____
A. hạt B. tia vũ trụ
C. thành phần D. bức xạ
Thông tin: cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds
Tạm dịch: tia vũ trụ không phải là thực sự là một dạng bức xạ, chúng gồm các hạt của nhiều loại khác nhau di chuyển nhanh chóng
Chọn B
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.
The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.
Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.
Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significant greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.
However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperature were too high and particles of matter were moving around much too rapidly. It was only after the one-minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased.
Why does the author mention "cosmic rays"?
A. To explain the abundance of hydrogen in the universe
B. To explain how the universe began
C. As an example of an unsolved astronomical puzzle
D. As part of a list of things containing helium
Kiến thức: Đọc hiểu
Giải thích:
Tại sao tác giả đề cập đến “các tia vũ trụ”?
A. Để giải thích sự phong phú của hydro trong vũ trụ B. Để giải thích về việc vũ trụ bắt đầu như thế nào
C. Để lấy ví dụ về câu đố về thiên văn chưa giải quyết D. Nó là một phần của danh sách những thứ có chứa khí heli
Thông tin: Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth
Tạm dịch: Hạt nhân helium cũng đã được tìm thấy là thành phần của các tia vũ trụ chiếu xuống Trái đất
Chọn D
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.
The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.
Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.
Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significant greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.
However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperature were too high and particles of matter were moving around much too rapidly. It was only after the one-minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased.
The creation of helium within stars ______
A. produces hydrogen as a by-product
B. causes helium to be much more abundant in old stars than in young st
C. produces energy
D. cannot be measured
Kiến thức: Đọc hiểu
Giải thích:
Việc tạo ra helium trong các ngôi sao ______
A. sản xuất hydro dưới dạng sản phẩm phụ B. làm cho helium có nhiều ở các ngôi sao tồn tại đã lâu hơn nhiều so với sao mới được hình thành
C. tạo ra năng lượng D. không thể đo được
Thông tin: Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce.
Tạm dịch: Helium được tạo ra trong các ngôi sao. Trong thực tế, phản ứng hạt nhân mà chuyển đổi Hydro thành Heli đảm nhiệm hầu hết năng lượng mà các ngôi sao tạo ra.
Chọn C
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.
The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.
Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.
Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significant greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.
However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperature were too high and particles of matter were moving around much too rapidly. It was only after the one-minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased.
What does the passage mainly explain?
A. How stars produce energy
B. When most of the helium in the universe was formed
C. Why hydrogen is abundant
D. The difference between helium and hydrogen
Kiến thức: Đọc hiểu
Giải thích:
Đoạn văn chủ yếu giải thích điều gì?
A. Các vì sao tạo ra năng lượng như thế nào
B. Thời điểm mà hầu hết khí heli trong vũ trụ được hình thành
C. Tại sao hydro lại dồi dào
‘ D. Sự khác biệt giữa heli và hydro
Thông tin: The universe has not existed long enough for this figure to be significant greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.
However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperature were too high and particles of matter were moving around much too rapidly. It was only after the one-minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased.
Tạm dịch: Vũ trụ đã không tồn tại đủ lâu để con số này là lớn hơn đáng kể. Do đó, nếu vũ trụ là có phần hơn 25 % Heli bây giờ, thì nó phải có được khoảng 25% Heli tại một thời điểm gần lúc nó hình thành.
Tuy nhiên, khi vũ trụ hình thành chưa đầy một phút, Heli đã không thể tồn tại. Các tính toán cho thấy rằng trước khi nhiệt độ thời gian này là quá cao và các hạt của vật chất đã được di chuyển xung quanh nhiều quá nhanh. Chỉ sau mốc một phút Heli mới thể tồn tại. Đến thời điểm này, vũ trụ đã quá nguội đến nỗi Nơtron và Proton có thể kết hợp vào nhau. Nhưng phản ứng hạt nhân dẫn đến sự hình thành của Heli đã hoàn thiện trong một thời gian tương đối ngắn. Sau khi vũ trụ được hình thành vài phút, việc tạo ra Heli đã không còn hiệu quả.
Chọn B
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.
The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.
Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.
Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significant greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.
However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperature were too high and particles of matter were moving around much too rapidly. It was only after the one-minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased.
According to the passage, helium is ________
A. the most prevalent element in quasars
B. difficult to detect
C. the oldest element in the universe
D. the second-most abundant element in the universe
Kiến thức: Đọc hiểu
Giải thích:
Theo đoạn văn, khí heli là ________
A. nguyên tố phổ biến nhất trong chuẩn tinh B. khó để phát hiện
C. nguyên tố lâu đời nhất trong vũ trụ D. nguyên tố phong phú thứ hai trong vũ trụ
Thông tin: The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.
Tạm dịch: Các yếu tố ngoài Hydro và Heli tồn tại với số lượng nhỏ đến nỗi chính xác khi nói rằng theo trọng lượng, vũ trụ có phần hơn 25 phần trăm heli tính và phần nào ít hơn 75 phần trăm Hydro.
Chọn D