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 43 to 50.
Life originated in the early seas less than a billion years after the 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 feed 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 form 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 them 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
According to the passage, what happened about 400 million years ago?
A. Many terrestrial life-forms died out
B. New life-forms on land developed at a rapid rate
C. The mega fossils were destroyed by floods
D. Life began to develop in the ancient seas
Đáp án B
Theo đoạn văn, điều gì đã diễn ra 400 năm về trước ?
A. Nhiều sinh thể trên cạn tiệt chủng
B. Nhiều dạng thể sống mới trên cạn phát triển với tốc độ nhanh
C. Đại hóa thạch bị hủy bởi bão lũ
D. Sự sống bắt đầu phát triển ở những biển cổ đại.
Dẫn chứng: “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.” ( Hơn thế, nhiều đại hóa thạch đã thể hiện rằng sự sống trên cạn đã xuất hiện và đa dạng hóa trong khoảng giữa giai đoạn Silur và giai đoạn Devon, khoảng hơn 400 năm trước.)