戴爾美語練功坊 托福閱讀實力測驗題4/25 - 英檢

戴爾美語練功坊…托福閱讀實力測驗試題(4/25日)


THE ORIGINS OF CETACEANS

It should be obvious that cetaceans-whales, porpoises, and dolphins-are
mammals.They breathe through lungs, not through gills, and give birth to
live young. Their streamlined bodies, the absence of hind legs, and the
presence of a fluke and blowhole cannot disguise their affinities with
land dwelling mammals. However, unlike the cases of sea otters and pinnipeds
(seals, sea lions, and walruses, whose limbs are functional both on land and
at sea), it is not easy to envision what the first whales looked like.
Extinct but already fully marine cetaceans are known from the fossil record.
(A)■ How was the gap between a walking mammal and a swimming whale bridged?
(B)■ Missing until recently were fossils clearly intermediate, or
transitional, between land mammals and cetaceans.

(C)■ Very exciting discoveries have finally allowed scientists to reconstruct
the most likely origins of cetaceans. (D)■ In 1979, a team looking for
fossils in northern Pakistan found what proved to be the oldest fossil whale.
The fossil was officially named Pakicetus in honor of the country where the
discovery was made. Pakicetus was found embedded in rocks formed from river
deposits that were 52 million years old. The river that formed these deposits
was actually not far from an ancient ocean known as the Tethys Sea.

The fossil consists of a complete skull of an archaeocyte, an extinct group
of ancestors of modern cetaceans. Although limited to a skull, the Pakicetus
fossil provides precious details on the origins of cetaceans. The skull is
cetacean-like but its jawbones lack the enlarged space that is filled with
fat or oil and used for receiving underwater sound in modern whales.
Pakicetus probably detected sound through the ear opening as in land mammals.
The skull also lacks a blowhole, another cetacean adaptation for diving.
Other features, however, show experts that Pakicetus is a transitional form
between a group of extinct flesh-eating mammals, the mesonychids, and
cetaceans. It has been suggested that Pakicetus fed on fish in shallow water
and was not yet adapted for life in the open ocean. It probably bred and gave
birth on land.

Another major discovery was made in Egypt in 1989. Several skeletons of another
early whale, Basilosaurus, were found in sediments left by the Tethys Sea and
now exposed in the Sahara desert. This whale lived around 40 million years ago,
12 million years after Pakicetus. Many incomplete skeletons were found but they
included, for the first time in an archaeocyte, a complete hind leg that
features a foot with three tiny toes. Such legs would have been far too small
to have supported the 50-foot-long Basilosaurus on land. Basilosaurus was
undoubtedly a fully marine whale with possibly nonfunctional, or vestigial,
hind legs.

An even more exciting find was reported in 1994, also from Pakistan. The now
extinct whale Ambulocetus natans ("the walking whale that swam") lived in the
Tethys Sea 49 million years ago. It lived around 3 million years after
Pakicetus but 9 million before Basilosaurus. The fossil luckily includes a good
portion of the hind legs. The legs were strong and ended in long feet very much
like those of a modern pinniped. The legs were certainly functional both on
land and at sea. The whale retained a tail and lacked a fluke, the major means
of locomotion in modern cetaceans. The structure of the backbone shows,
however, that Ambulocetus swam like modern whales by moving the rear portion of
its body up and down, even though a fluke was missing. The large hind legs were
used for propulsion in water. On land, where it probably bred and gave birth,
Ambulocetus may have moved around very much like a modern sea lion. It was
undoubtedly a whale that linked life on land with life at sea.

Glossary:
Fluke: the two parts that constitute the large triangular tail of a whale
Blowhole: ahole in the top of the head used for breathing

1. In paragraph 1, what does the author say about the presence of a blowhole in
cetaceans?
(A) It clearly indicates that cetaceans are mammals.
(B) It cannot conceal the fact that cetaceans are mammals.
(C) It is the main difference between cetaceans and land-dwelling mammals.
(D) It cannot yield clues about the origins of cetaceans.

2. Which of the following can be inferred from paragraph 1 about early sea
otters?
(A) It is not difficult to imagine what they looked like
(B) There were great numbers of them.
(C) They lived in the sea only.
(D) They did not leave many fossil remains.

3. According to the passage, Pakicetus and modern cetaceans have similar
(A) Hearing structures
(B) Adaptations for diving
(C) Skull shapes
(D) Breeding locations

4. The hind leg of Basilosaurus was a significant find because it showed that
Basilosaurus
(A) Lived later than Ambulocetus natans
(B) Lived at the same time as Pakicetus
(C) Was able to swim well
(D) Could not have walked on land

5. It can be inferred that Basilosaurus bred and gave birth in which of the
following locations
(A) on land
(B) both on land and at sea
(C) in shallow water
(D) in a marine environment

6. Why does the author use the word luckily in mentioning that the Ambulocetus
natans fossil included hind legs?
(A) Fossil legs of early whales are a rare find.
(B) The legs provided important information about the evolution of cetaceans.
(C) The discovery allowed scientists to reconstruct a complete skeleton of the
whale.
(D) Until that time, only the front legs of early whales had been discovered.

Answers:
1. 根據題幹-- What does the author say about the presence of a blowhole in
cetaceans?
原文定位第一段:
Their streamlined bodies, the absence of hind legs, and the presence of a fluke
and blowhole cannot disguise their affinities with land dwelling mammals.
答案為: B

2. Which of the following can be inferred from paragraph 1 about early sea
otters?
此題主要測驗inference (推論) --- 技巧為搜尋(1) 轉折語; (2) 極致詞 ; (3) 強調字
詞.
However, unlike the cases of sea otters and pinnipeds (seals, sea lions, and
walruses, whose limbs are functional both on land and at sea), it is not easy
to envision what the first whales looked like.
原文敘述 --- 不像海獺一樣, 要想像出第一隻鯨魚之樣貌並不容易.
然而, 題目問sea otters, 尋找該句首出現 unlike ... 故而選出其對立之論述.
答案為 A .

3. According to the passage, Pakicetus and modern cetaceans have similar
--- The fossil consists of a complete skull of an archaeocyte, an extinct group
of ancestors of modern cetaceans. Although limited to a skull, the Pakicetus
fossil provides precious details on the origins of cetaceans.
答案為 C .

4. The hind leg of Basilosaurus was a significant find because it showed that
Basilosaurus
--- 題幹中之關鍵字詞為 The hind leg of Basilosaurus
原文: Many incomplete skeletons were found but they included, for the first
time in an archaeocyte, a complete hind leg that features a foot with three
tiny toes. Such legs would have been far too small to have supported the
50-foot-long Basilosaurus on land. Basilosaurus was undoubtedly a fully marine
whale with possibly nonfunctional, or vestigial, hind legs.
答案為 D .

5. It can be inferred that Basilosaurus bred and gave birth in which of the
following locations
--- 題目推論 Basilosaurus 之棲息環境為何?
Basilosaurus was undoubtedly a fully marine whale with
possibly nonfunctional, or vestigial, hind legs.
答案為 D.

6. Why does the author use the word luckily in mentioning that the Ambulocetus
natans fossil included hind legs?
--- 此題主要為 rhetorical purpose (修辭目的) .
An even more exciting find was reported in 1994, also from Pakistan. The now
extinct whale Ambulocetus natans ("the walking whale that swam") lived in the
Tethys Sea 49 million years ago. It lived around 3 million years after
Pakicetus but 9 million before Basilosaurus. The fossil luckily includes a good
portion of the hind legs. The legs were strong and ended in long feet very much
like those of a modern pinniped.
答案為 B.



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