司法三等
105年
[公證人] 法學知識與英文(包括中華民國憲法、法學緒論、英文)
第 44 題
📖 題組：
Some 66m years ago Earth was hit by a space rock reckoned to have been 10km across. The resulting chaos caused the extinction of dinosaurs and many other species, opening the way for the age of mammals－and ultimately humans. It also left a big hole in what is now southern Mexico. That hole is one of only three known of similar dimensions (the other two are Vredefort in South Africa and Sudbury in Canada). And this is odd. For, during the billions of years that Earth has had a solid crust, many more than three big asteroids might have been expected to have hit it. That thought led Brandon Johnson of the MIT and Timothy Bowling of Purdue University in Indiana, to wonder how many other craters have vanished, either by erosion or by being swallowed into Earth’s interior as its crust moves around, and therefore whether it is likely that some have survived and been overlooked. They have just published their analysis in Geology. Earth’s crust formed more than 4 billion years ago, but the oldest surviving blocks of it large enough to harbor craters date back only 3.5 billion years. What is known of the sizes and orbits of modern asteroids suggests that, if things have not changed over the aeons, about 14 big asteroids (defined as having a diameter of more than 7.4km, which would cause a crater at least 85km in diameter) should hit Earth every billion years. That means 49, give or take seven, over the past 3.5 billion years. Such impacts may have been more common in the past, when more big asteroids were around. Allowing for this, Earth would have been hit by 113, give or take 11, of them. Either way, a lot of craters are missing.
Some 66m years ago Earth was hit by a space rock reckoned to have been 10km across. The resulting chaos caused the extinction of dinosaurs and many other species, opening the way for the age of mammals－and ultimately humans. It also left a big hole in what is now southern Mexico. That hole is one of only three known of similar dimensions (the other two are Vredefort in South Africa and Sudbury in Canada). And this is odd. For, during the billions of years that Earth has had a solid crust, many more than three big asteroids might have been expected to have hit it. That thought led Brandon Johnson of the MIT and Timothy Bowling of Purdue University in Indiana, to wonder how many other craters have vanished, either by erosion or by being swallowed into Earth’s interior as its crust moves around, and therefore whether it is likely that some have survived and been overlooked. They have just published their analysis in Geology. Earth’s crust formed more than 4 billion years ago, but the oldest surviving blocks of it large enough to harbor craters date back only 3.5 billion years. What is known of the sizes and orbits of modern asteroids suggests that, if things have not changed over the aeons, about 14 big asteroids (defined as having a diameter of more than 7.4km, which would cause a crater at least 85km in diameter) should hit Earth every billion years. That means 49, give or take seven, over the past 3.5 billion years. Such impacts may have been more common in the past, when more big asteroids were around. Allowing for this, Earth would have been hit by 113, give or take 11, of them. Either way, a lot of craters are missing.
How large is the crater created in southern Mexico by the asteroid 66m years ago?
- A 10km across in diameter.
- B 85km in diameter.
- C 7.4km in diameter.
- D Not mentioned in the article.
思路引導 VIP
請再次閱讀第一段關於墨西哥『大洞』（hole）的描述，並試著找找看：文中是否有任何一個數字是直接用來描述這個『洞』本身的尺寸，還是那些數字其實都在形容『撞擊物』或其他假設情況呢？
🤖
AI 詳解
AI 專屬家教
🙄 喔，不錯嘛，沒被那些數字騙到。
- 勉強及格：這題說穿了就是考你會不會「腦補」。你竟然能從那些看似相關的數字堆裡，看出題目根本沒給墨西哥那個坑的確切大小，還算有點批判性閱讀能力。至少，你沒蠢到去選那些一眼就能看出是煙霧彈的選項。
- 觀念釐清：文中明白講了撞擊物有 $10\text{ km}$ 寬，也提到直徑大於 $7.4\text{ km}$ 的小行星能製造至少 $85\text{ km}$ 的大坑。但對於「墨西哥那個洞」，文章就是輕描淡寫地說個 a big hole，然後就沒了。看來你還知道「小行星的尺寸」跟「它砸出來的坑有多大」是兩回事，恭喜你，沒完全混淆。
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