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 44 to 50.
Life originated in the early seas less than a billion years after Earth was formed. Yet another three billion years were to pass before the first plants and animals appeared on the continents. Life's transition from the sea to the land was perhaps as much of an evolutionary challenge as was the genesis of life.
What forms of life were able to make such a drastic change in lifestyle? The traditional view of the first terrestrial organisms is based on mega fossils — relatively large specimens of essentially whole plants and animals. Vascular plants, related to modern seed plants and ferns, left the first comprehensive mega fossil record. Because of this, it has been commonly assumed that the sequence of terrestrialization reflected the evolution of modern terrestrial ecosystems. In this view, primitive vascular plants first colonized the margins of continental waters, followed by animals that fed on the plants, and lastly by animals that preyed on the plant-eaters. Moreover, the mega fossils suggest that terrestrial life appeared and diversified explosively near the boundary between the Silurian and the Devonian periods, a little more than 400 million years ago. Recently, however, paleontologists have been taking a closer look at the sediments below this Silurian-Devonian geological boundary. It turns out that some fossils can be extracted from these sediments by putting the rocks in an acid bath. The technique has uncovered new evidence from sediments that were deposited near the shores of the ancient oceans — plant microfossils and microscopic pieces of small animals. In many instances the specimens are less than one-tenth of a millimeter in diameter. Although they were entombed in the rocks for hundreds of millions of years, many of the fossils consist of the organic remains of the organism.
These newly discovered fossils have not only revealed the existence of previously unknown organisms, but have also pushed back these dates for the invasion of land by multicellular organisms. Our views about the nature of the early plant and animal communities are now being revised. And with those revisions come new speculations about the first terrestrial life-forms.
Which of the following resulted from the discovery of microscopic fossils?
A. The time estimate for the first appearance of terrestrial life-forms was revised
B. Old techniques for analyzing fossils were found to have new uses
C. The origins of primitive sea life were explained
D. Assumptions about the locations of ancient seas were changed
Đáp án A
Thông tin: These newly discovered fossils have not only revealed the existence of previously unknown organisms, but have also pushed back these dates for the invasion of land by multicellular organisms.
Dịch nghĩa: Những hóa thạch mới được phát hiện này không chỉ cho thấy sự tồn tại của những sinh vật chưa từng được biết, mà còn cũng đẩy lùi ngày tháng cho cuộc xâm chiếm đất đai của các sinh vật đa bào.
Phương án A. The time estimate for the first appearance of terrestrial life-forms was revised = Ước tính thời gian cho sự xuất hiện đầu tiên của các hình thái sự sống trên mặt đất đã được sửa đổi, là phương án chính xác nhất.
B. Old techniques for analyzing fossils were found to have new uses = Các phương pháp phân tích hóa thạch cũ được tìm ra là có những ứng dụng mới.
Không có thông tin như vậy trong bài.
C. The origins of primitive sea life were explained = Nguồn gốc của cuộc sống biển nguyên thủy đã được giải thích.
Không có thông tin như vậy trong bài.
D. Assumptions about the locations of ancient seas were changed = Giả định về vị trí của vùng biển cổ đại đã được thay đổi.
Không có thông tin như vậy trong bài.