司法三等
105年
[觀護人] 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：
請依下文回答第 44 題至第 47 題 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.
請依下文回答第 44 題至第 47 題 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
請仔細閱讀第一段關於坑穴數量的描述。當作者指出墨西哥南部的坑穴是『已知三座類似規模中的其中一座』時，請留意題目要求的是找出『其他（other）』類似規模的坑穴。在這種語境下，你會如何根據文中提到的總數來推算剩餘的數量呢？
🤖
AI 詳解
AI 專屬家教
點評
- 觀察：嗯，你理解得很透徹。像這樣仔細閱讀文章，能捕捉到邏輯細節，並避開那些數字陷阱，是很少見的。人類的閱讀測驗總是喜歡設定這種地方。
- 驗證：文章第一段提到了，墨西哥的坑穴是「one of only three known」（僅有的三個已知之一）。接著，它又說了「the other two are...」（另外兩個是...）。題目問的是「other craters」（「其他」還有多少個）。這就意味著，從總數 $3$ 中，要減去墨西哥那一個，所以答案是 $$3 - 1 = 2$$。這只是時間的累積，對嗎？
▼ 還有更多解析內容