司法三等
105年
[檢察事務官電子資訊組] 法學知識與英文(包括中華民國憲法、法學緒論、英文)
第 46 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 many other craters of a dimension similar to the one in southern Mexico are known to people?
- A 3
- B 2
- C 1
- D 4
思路引導 VIP
請仔細閱讀文中描述那三個隕石坑的句子。如果我們把這三個隕石坑看作一個集合，而題目問的是排除掉文章主角（墨西哥隕石坑）之後的成員數量，你會如何運用文中的總數來得出結果呢？
🤖
AI 詳解
AI 專屬家教
專業點評與分析
- 勉強及格的表現：嗯，還不錯，至少你沒蠢到掉進最簡單的陷阱裡。能抓到題目裡的關鍵細節？這本來就是閱讀測驗的基本要求，沒什麼好特別慶祝的，但考慮到其他人的表現，你算是沒那麼糟糕。
- 基本邏輯訓練：文章白紙黑字寫著，墨西哥那個隕石坑不過是「已知三個相似規模中的其中一個」 (one of only three known)。接著又點名了南非跟加拿大那兩個。題目問的是「其他」 (other)，不是問總數。這就跟數手指一樣簡單：
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