託福TPO8閱讀真題Part2文本及題目答案

託福TPO是我們託福閱讀的重要參考資料，爲了方便大家備考，下面小編給大家整理了託福TPO8閱讀真題Part2文本及題目答案，希望大家喜歡。

       託福TPO8閱讀真題Part2

Extinction of the Dinosaurs

Paleozoic Era 334 to 248 million years ago

Mesozoic Era 245 to 65 million years ago

-Triassic Period

-Jurassic Period

-Cretaceous Period

Cenozoic Era 65 million years ago to the present

Paleontologists have argued for a long time that the demise of the dinosaurs was caused by climatic alterations associated with slow changes in the positions of continents and seas resulting from plate tectonics. Off and on throughout the Cretaceous (the last period of the Mesozoic era, during which dinosaurs flourished), large shallow seas covered extensive areas of the continents. Data from diverse sources, including geochemical evidence preserved in seafloor sediments, indicate that the Late Cretaceous climate was milder than today's. The days were not too hot, nor the nights too cold. The summers were not too warm, nor the winters too frigid. The shallow seas on the continents probably buffered the temperature of the nearby air, keeping it relatively constant.

At the end of the Cretaceous, the geological record shows that these seaways retreated from the continents back into the major ocean basins. No one knows why. Over a period of about 100,000 years, while the seas pulled back, climates around the world became dramatically more extreme: warmer days, cooler nights; hotter summers, colder winters. Perhaps dinosaurs could not tolerate these extreme temperature changes and became extinct.

If true, though, why did cold-blooded animals such as snakes, lizards, turtles, and crocodiles survive the freezing winters and torrid summers? These animals are at the mercy of the climate to maintain a livable body temperature. It's hard to understand why they would not be affected, whereas dinosaurs were left too crippled to cope, especially if, as some scientists believe, dinosaurs were warm-blooded. Critics also point out that the shallow seaways had retreated from and advanced on the continents numerous times during the Mesozoic, so why did the dinosaurs survive the climatic changes associated with the earlier fluctuations but not with this one? Although initially appealing, the hypothesis of a simple climatic change related to sea levels is insufficient to explain all the data.

Dissatisfaction with conventional explanations for dinosaur extinctions led to a surprising observation that, in turn, has suggested a new hypothesis. Many plants and animals disappear abruptly from the fossil record as one moves from layers of rock documenting the end of the Cretaceous up into rocks representing the beginning of the Cenozoic (the era after the Mesozoic). Between the last layer of Cretaceous rock and the first layer of Cenozoic rock, there is often a thin layer of clay. Scientists felt that they could get an idea of how long the extinctions took by determining how long it took to deposit this one centimeter of clay and they thought they could determine the time it took to deposit the clay by determining the amount of the element iridium (Ir) it contained.

Ir has not been common at Earth's since the very beginning of the planet's history. Because it usually exists in a metallic state, it was preferentially incorporated in Earth's core as the planet cooled and consolidated. Ir is found in high concentrations in some meteorites, in which the solar system's original chemical composition is preserved. Even today, microscopic meteorites continually bombard Earth, falling on both land and sea. By measuring how many of these meteorites fall to Earth over a given period of time, scientists can estimate how long it might have taken to deposit the observed amount of Ir in the boundary clay. These calculations suggest that a period of about one million years would have been required. However, other reliable evidence suggests that the deposition of the boundary clay could not have taken one million years. So the unusually high concentration of Ir seems to require a special explanation.

In view of these facts, scientists hypothesized that a single large asteroid, about 10 to 15 kilometers across, collided with Earth, and the resulting fallout created the boundary clay. Their calculations show that the impact kicked up a dust cloud that cut off sunlight for several months, inhibiting photosynthesis in plants; decreased surface temperatures on continents to below freezing; caused extreme episodes of acid rain; and significantly raised long-term global temperatures through the greenhouse effect. This disruption of food chain and climate would have eradicated the dinosaurs and other organisms in less than fifty years.

Paragraph 1: Paleontologists have argued for a long time that the demise of the dinosaurs was caused by climatic alterations associated with slow changes in the positions of continents and seas resulting from plate tectonics. Off and on throughout the Cretaceous (the last period of the Mesozoic era, during which dinosaurs flourished), large shallow seas covered extensive areas of the continents. Data from diverse sources, including geochemical evidence preserved in seafloor sediments, indicate that the Late Cretaceous climate was milder than today's. The days were not too hot, nor the nights too cold. The summers were not too warm, nor the winters too frigid. The shallow seas on the continents probably buffered the temperature of the nearby air, keeping it relatively constant.

　託福TPO8閱讀題目Part2

1. According to paragraph 1, which of the following is true of the Late Cretaceous climate?

Paragraph 2: At the end of the Cretaceous, the geological record shows that these seaways retreated from the continents back into the major ocean basins. No one knows why. Over a period of about 100,000 years, while the seas pulled back, climates around the world became dramatically more extreme: warmer days, cooler nights; hotter summers, colder winters. Perhaps dinosaurs could not tolerate these extreme temperature changes and became extinct.

2. Which of the following reasons is suggested in paragraph 2 for the extinction of the dinosaurs?

Paragraph 3: If true, though, why did cold-blooded animals such as snakes, lizards, turtles, and crocodiles survive the freezing winters and torrid summers? These animals are at the mercy of the climate to maintain a livable body temperature. It's hard to understand why they would not be affected, whereas dinosaurs were left too crippled to cope, especially if, as some scientists believe, dinosaurs were warm-blooded. Critics also point out that the shallow seaways had retreated from and advanced on the continents numerous times during the Mesozoic, so why did the dinosaurs survive the climatic changes associated with the earlier fluctuations but not with this one? Although initially appealing, the hypothesis of a simple climatic change related to sea levels is insufficient to explain all the data.

3. Why does the author mention the survival of "snakes, lizards, turtles, and crocodiles" in paragraph 3?

4. The word "cope" in the passage is closest in meaning to

5. According to paragraph 3, which of the following is true of changes in climate before the Cretaceous period and the effect of these changes on dinosaurs?

6.The word "fluctuations" in the passage is closest in meaning to

Paragraph 4: Dissatisfaction with conventional explanations for dinosaur extinctions led to a surprising observation that, in turn, has suggested a new hypothesis. Many plants and animals disappear abruptly from the fossil record as one moves from layers of rock documenting the end of the Cretaceous up into rocks representing the beginning of the Cenozoic (the era after the Mesozoic). Between the last layer of Cretaceous rock and the first layer of Cenozoic rock, there is often a thin layer of clay. Scientists felt that they could get an idea of how long the extinctions took by determining how long it took to deposit this one centimeter of clay and they thought they could determine the time it took to deposit the clay by determining the amount of the element iridium (lr) it contained.

7. Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? In correct choices change the meaning in important ways or leave out essential information.

Paragraph 4: Dissatisfaction with conventional explanations for dinosaur extinctions led to a surprising observation that, in turn, has suggested a new hypothesis. Many plants and animals disappear abruptly from the fossil record as one moves from layers of rock documenting the end of the Cretaceous up into rocks representing the beginning of the Cenozoic (the era after the Mesozoic). Between the last layer of Cretaceous rock and the first layer of Cenozoic rock, there is often a thin layer of clay. Scientists felt that they could get an idea of how long the extinctions took by determining how long it took to deposit this one centimeter of clay and they thought they could determine the time it took to deposit the clay by determining the amount of the element iridium (Ir) it contained.

8. In paragraph 4, all the following questions are answered EXCEPT:

Paragraph 5: Ir has not been common at Earth's since the very beginning of the planet's history. Because it usually exists in a metallic state, it was preferentially incorporated in Earth's core as the planet cooled and consolidated. Ir is found in high concentrations in some meteorites, in which the solar system's original chemical composition is preserved. Even today, microscopic meteorites continually bombard Earth, falling on both land and sea. By measuring how many of these meteorites fall to Earth over a given period of time, scientists can estimate how long it might have taken to deposit the observed amount of Ir in the boundary clay. These calculations suggest that a period of about one million years would have been required. However, other reliable evidence suggests that the deposition of the boundary clay could not have taken one million years. So the unusually high concentration of Ir seems to require a special explanation.

9. The word "bombard" in the passage is closest in meaning to

10. Paragraph 5 implies that a special explanation of Ir in the boundary clay is needed because

Paragraph 6: In view of these facts, scientists hypothesized that a single large asteroid, about 10 to 15 kilometers across, collided with Earth, and the resulting fallout created the boundary clay. Their calculations show that the impact kicked up a dust cloud that cut off sunlight for several months, inhibiting photosynthesis in plants; decreased surface temperatures on continents to below freezing; caused extreme episodes of acid rain; and significantly raised long-term global temperatures through the greenhouse effect. This disruption of food chain and climate would have eradicated the dinosaurs and other organisms in less than fifty years.

11. The word "disruption" in the passage is closest in meaning to

12. Paragraph 6 mentions all of the following effects of the hypothesized asteroid collision EXCEPT

Paragraph 5: Ir has not been common at Earth's since the very beginning of the planet's history. Because it usually exists in a metallic state, it was preferentially incorporated in Earth's core as the planet cooled and consolidated. Ir is found in high concentrations in some meteorites, in which the solar system's original chemical composition is preserved. Even today, microscopic meteorites continually bombard Earth, falling on both land and sea. By measuring how many of these meteorites fall to Earth over a given period of time, scientists can estimate how long it might have taken to deposit the observed amount of Ir in the boundary clay. ■ These calculations suggest that a period of about one million years would have been required. ■However, other reliable evidence suggests that the deposition of the boundary clay could not have taken one million years. ■So the unusually high concentration of Ir seems to require a special explanation. ■

13. Look at the four squares [■] that indicate where the following sentence could be added to the passage.

Consequently, the idea that the Ir in the boundary clay came from microscopic meteorites cannot be accepted.

Where would the sentence best fit?

14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.

For a long time scientists have argued that the extinction of the dinosaurs was related to climate change.

Answer choices

託福TPO8閱讀答案Part2

參考答案：

1. ○4

2. ○3

3. ○2

4. ○1

5. ○1

6. ○4

7. ○1

8.○1

9. ○2

10. ○4

11. ○2

12. ○3

13. ○3

14. A simple climate change

The abruptness of extinctions

Some scientists hypothesize

託福TPO8閱讀翻譯：Part2

參考翻譯：恐龍的滅絕

很長時間以來，古生物學家們認爲恐龍的滅亡是與因地質構造而引起的海洋和大陸位置變遷相關的氣候變化所致。在整個白堊紀(中生代的最後的一段時間，這時恐龍正值繁盛)，廣闊的淺海覆蓋了大量的陸地。各方面的數據，包括海牀沉積中的地理化學證據，都表明白堊紀後期的氣候比現在的氣候要溫和得多。白天不是很熱，夜間也不是很寒冷。夏天不是太炎熱，而冬天也不是太寒冷。大陸上的淺海可能使其附近的空氣少受影響，以保持相對穩定的溫度。

在白堊紀後期，地質資料表明這些淺海都從大陸退回到主要的海洋盆地內了，沒有人明白爲什麼。大約在100 000年內，海洋收縮了，世界的氣候也隨之變得更極端：白天更熱，夜間更冷，夏天更炎熱，冬天更寒冷。恐龍或許就是因爲無法忍受這種嚴峻的氣溫變化因而滅絕。

如果真是這樣，那麼爲什麼冷血動物，比如蛇類、蜥蜴、烏龜和鱷魚卻能夠倖免於寒冬和酷夏呢?這些動物都是依賴於氣溫以使其身體保持適合生存的溫度。很難理解它們爲什麼毫不受影響，然而恐龍卻如此的無能以至於無法適應，尤其是有些科學家認爲恐龍是熱血動物。批評者們也指出淺海在中生代曾有過無數次的進入大陸而又退回盆地的過程，所以爲什麼恐龍在前面的海洋起伏中能倖免於難，而在這一次中卻不能呢?儘管最初人們這樣認爲，但是簡單的與海平面高度有關的氣候變化假設是不足以解釋所有數據的。

對傳統的關於恐龍滅絕解釋的不滿使得人們反過來驚奇的發現，從而產生了新的假設。當人們對比白堊紀後期的岩層資料和新生代(中生代後面的一個時期)早期的資料時發現很多植物和動物都突然地消失了。在白堊紀最後的一層岩石和新生代的第一層岩石之間，常有一層很薄的粘土。科學家們感覺到他們可以通過確定這層一釐米厚的粘土層中元素銥的含量來推測其的沉積時間，進而推測大滅絕所用的時間。

自從地球以來，銥元素在地球的表面上就不常見。因爲它通常是以金屬狀態存在，並隨着地球的冷卻和固結而優先地合併到地核中了。在一些隕石中，依可能會高度富集，而這裏常保存着太陽系內原始的化學組成。直到今天，小型的隕石也在連續不斷地撞擊地球，並掉落在陸地和海洋中。通過確定在一段給定時間內掉落在地球上的這種隕石的數量，科學家們就可以確定沉積隔層粘土的形成時間。這種計算表明形成這種沉積可能需要一百萬年。然而其他可靠的證據則表明沉積這層粘土不可能花費了一百萬年。所以這種不正常的銥的富集可能需要一種特殊的解釋。