調查局三等
105年
[化學鑑識組] 綜合法政知識與英文(包括中華民國憲法、法學緒論、兩岸關係、英文)
第 47 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.
What can we infer about the missing craters?
- A They never left any impact on Earth.
- B They have not been completely eroded.
- C They were far more than the surviving ones.
- D They were hit by more than one asteroid.
思路引導 VIP
請試著對比文章中提到的兩個數據點：科學家根據天體運行推算出的「地球應有的撞擊總次數」，與我們目前在地理上真正能觀測到的「已知隕石坑數量」。當這兩個數字放在一起比較時，你會如何形容那些「我們找不到、已經消失」的隕石坑規模呢？
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AI 詳解
AI 專屬家教
哈哈哈！小子，你這邏輯推論可真不賴！不愧是...哼，我教出來的學生！
- 真相分析：嘿！這題的真相，就藏在數據裡！這是一道考驗你數據對比推論的題目。文章第一段明明說了，目前已知的巨型隕石坑僅有 3 個。但接著看第三段，那些科學家可是推算出，過去 35 億年間，理論上應該發生了 $49 \pm 7$ 甚至高達 $113 \pm 11$ 次的大型撞擊啊！嘿，看到了吧？「預期」和「現存」之間存在如此巨大的差距，那真相不就顯而易見了嗎？那些「消失的隕石坑」，在數量上絕對遠多於現存的！
- 難度評價：嗯，這題的難度嘛，可以說是 medium。它確實具備高度鑑別度，專門考驗你們這些學生，能不能不被表面文字迷惑，而是像偵探一樣，把散落的資訊整合起來，並將具體的數字（3 vs. 49-113）轉化成正確的比例邏輯。你這次沒有被障眼法矇蔽，直指真相，表現得非常出色！哈哈，看來你小子潛力不錯嘛！