Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.
Quite different from storm surges are the giant sea waves called tsunamis, which derive their name from the Japanese expression for “high water in a harbor.” These waves are also referred to by the general public as tidal waves, although they have relatively little to do with tides. Scientists often referred to them as seismic sea waves, far more appropriate in that they do result from undersea seismic activity.
Tsunamis are caused when the sea bottom suddenly moves, during an underwater earthquake or volcano for example, and the water above the moving earth is suddenly displaced. This sudden shift of water sets off a series of waves. These waves can travel great distances at speeds close to 700 kilometers per hour. In the open ocean, tsunamis have little noticeable amplitude, often no more than one or two meters. It is when they hit the shallow waters near the coast that they increase in height, possibly up to 40 meters.
Tsunamis often occur in the Pacific because the Pacific is an area of heavy seismic activity. Two areas of the Pacific well accustomed to the threat of tsunamis are Japan and Hawaii. Because the seismic activity that causes tsunamis in Japan often occurs on the ocean bottom quite close to the islands, the tsunamis that hit Japan often come with little warning and can, therefore, prove disastrous. Most of the tsunamis that hit the Hawaiian Islands, however, originate thousands of miles away near the coast of Alaska, so these tsunamis have a much greater distance to travel and the inhabitants of Hawaii generally have time for warning of their imminent arrival.
Tsunamis are certainly not limited to Japan and Hawaii. In 1755, Europe experienced a calamitous tsunami, when movement along the fault lines near the Azores caused a massive tsunami to sweep onto the Portuguese coast and flood the heavily populated area around Lisbon. The greatest tsunami on record occurred on the other side of the world in 1883 when the Krakatoa volcano underwent a massive explosion, sending waves more than 30 meters high onto nearby Indonesian islands; the tsunami from this volcano actually traveled around the world and was witnessed as far away as the English Channel.
According to the passage, all of the following are true about tidal waves except that _____.
A. they are the same as tsunamis
B. they refer to the same phenomenon as seismic sea waves
C. they are caused by sudden changes in high and low tides
D. this terminology is not used by the scientific community
Đáp án C
Chúng ta scan từ tidal waves để tìm ra đáp án là C. they are caused by sudden changes in high and low tides (chúng được gây ra bởi sự thay đổi đột ngột của thuỷ triều lên và xuống. Ở dòng 2 +3 đoạn 1 có nhắc tới “These waves are also referred to by the general public as tidal waves, although they have relatively little to do with tides” Người dân xem những con sóng này như là những con sóng thuỷ triều mặc dù chúng gần như không liên quan đến thuỷ triều.
Phương án A được tìm thấy ở dòng 1 +2 + 3 đoạn 1: “Quite different from storm surges are the giant sea waves called tsunamis, which derive their name from the Japanese expression for “high water in a harbor.” These waves are also referred to by the general public as tidal waves” Những con sóng này cũng chính là tsunamis
Phương án B và D được tìm thấy ở dòng 3 đoan 1: “Scientists often referred to them as seismic sea waves, far more appropriate in that they do result from undersea seismic activity” Các nhà khoa học thường đề cập đến chúng như là các cơn sóng biển địa chấn, thuật ngữ này phù hợp hơn vì chúng được gây nên bởi hoạt động địa chấn dưới biển.