职称英语考试

试题来源：2011年职称英语等级考试真题（理工类A级）
【单选题】

Earth Rocks On
　　Most of the time, the ground feels solid beneath our feet. That's comforting. But it's also misleading because there's actually a lot going on underground. Masses of land (called plates) slip, slide, and bump against each other, slowly changing the shape of continents and oceans over millions and billions of years.
　　Scientists know that Earth formed about 4.5 billion years ago. They also know that our planet was hot at first. As it cooled, its outermost layer, called the crust, eventually formed moving plates. Exactly when this shift happened, however, is an open question.
　　Now, an international group of researchers has an answer. They've found new evidence suggesting that Earth's crust (地壳) started shifting at least 3.8 billion years ago. The new estimate is 1.3 billion years earlier than previous ones.
　　Not long before 3.8 billion years ago, lots of asteroids (小行星) were pummeling Earth, keeping its crust in a hot, molten state. After the hard crust formed, much of it sank at various times into the planet's hot insides. There, it melted before returning to the surface as lava.
　　In some places, however, the crust never sank. One of the oldest such places is in Greenland, in an area called the Isua supracrustal(上地壳) belt. The rocky crust there is between 3.7 and 3.8 billion years old. The belt was once part of the seafloor, but now it is exposed to air.
　　The researchers recently look at the Isua supracrustal belt. They noticed long, parallel cracks in the rock that have been filled in with a type of volcanic rock.
　　To explain this structure, the scientists propose that tension in the crust caused the seafloor to crack open long ago. Hot, liquid rock, called magma(岩浆), flowed up slowly from deep inside Earth to fill the cracks. Finally, the area cooled, forming what we see today.
　　That explanation, plus chemical clues inside the rock, suggests that the Isua supracrustal belt was once part of a plate under the ocean, beginning around 3.8 billion years ago.
　　16 The ground beneath our feet is indeed still.
　　A Right           B Wrong           C Not mentioned
　　17 The shape of lands and oceans are slowly changed with the movements of plates.
　　A Right           B Wrong           C Not mentioned
　　18 Earth cooled down shortly after it was formed.
　　A Right           B Wrong           C Not mentioned
19 Scientists once estimated that Earth's crust started shifting three billion years ago.
　　A Right           B Wrong           C Not mentioned
　　20.It took a long time for the melted crust to become hard.
　　A Right           B Wrong           C Not mentioned
　　21.The formation of the Isua supracrustal belt is thought to have started about 3.8 billion years ago.
　　A Right           B Wrong           C Not mentioned
　　22. The lsua supracrustal belt is now a popular holiday resort.
　　A Right           B Wrong           C Not mentioned

网考网参考答案：B、A、C、B、C、A、C
大数据分析：根据网考网与考试题库的统计分析，该试题：
10%的考友选择了A选项
75%的考友选择了B选项
15%的考友选择了C选项
考友解析与评论：
 · 出题的估计语文没学好
 · 我就纳闷了，为什么要选B、A、C、B、C、A、C
 · 这个答案是有歧义