Câu hỏi:
11/05/2023 483
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 megafossils ― relatively large specimens of essentially whole plants and animals. Vascular plants, related to modern seed plants and ferns, left the first comprehensive megafossil 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 megafossils 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 speculation about the first terrestrial life-forms.
The word “drastic” in line 5 is closest in meaning to
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 megafossils ― relatively large specimens of essentially whole plants and animals. Vascular plants, related to modern seed plants and ferns, left the first comprehensive megafossil 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 megafossils 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 speculation about the first terrestrial life-forms.
The word “drastic” in line 5 is closest in meaning to
Đáp án chính xác
Câu hỏi trong đề:
Trắc nghiệm tổng hợp Tiếng anh có đáp án 2023 !!
Sách mới 2k7: Tổng ôn Toán, Lí, Hóa, Văn, Sử, Địa…. kỳ thi tốt nghiệp THPT Quốc gia 2025, đánh giá năng lực (chỉ từ 110k).
Quảng cáo
Trả lời:
Giải bởi Vietjack
Lời giải:
Đáp án: B
1. drastical = radical: triệt để
Nhà sách VIETJACK:
CÂU HỎI HOT CÙNG CHỦ ĐỀ
Câu 2:
The telescope will photograph distant galaxies, ______ an attempt to understand their past.
Xem đáp án »
11/05/2023
11,666
Câu 5:
Even if rural areas are winning or losing from increased trade, however, remains uncertain.
Xem đáp án »
11/05/2023
7,002
Câu 7:
We ____ go to work by car. Sky train is a wise choice during rush hour.
Xem đáp án »
11/05/2023
6,080
Bình luận
🔥 Đề thi HOT:
-
500 bài Đọc điền ôn thi Tiếng anh lớp 12 có đáp án (Đề 1)
-
Topic 1: Family life
-
Bộ câu hỏi: [TEST] Từ loại (Buổi 1) (Có đáp án)
-
Topic 31: Global warming (Phần 2)
-
Đề thi học kì 1 Tiếng anh 12 có đáp án( đề 12 )
-
Trắc nghiệm tổng hợp Tiếng anh có đáp án 2023 (Phần 1)
-
Bộ 5 đề thi cuối kì 1 Tiếng Anh 12 Friends Global có đáp án (đề 1)
-
Bộ câu hỏi: Các dạng thức của động từ (to v - v-ing) (Có đáp án)
về câu hỏi!