第2部分：閱讀判斷(第16～22題，每題1分，共7分)

下面的短文后列出了7個句子，請根據(jù)短文的內容對每個句子做出判斷：如果該句提供的是正確信息，請選擇A；如果該句提供的是錯誤信息，請選擇B；如果該句的信息文中沒有提及，請選擇C。

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 (地殼) 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(上地殼) 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(巖漿), 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

16 B 本文第一段提到 "盡管我們感覺腳下的大地在大多數(shù)的時候是實心固體的，但實際上地下的物質一直在運動，這種運動慢慢改變著大陸和海洋的形狀"。提干認為"我們腳 下的地球是靜止的"不符合文意，所以選擇 B。

17 A 本文第一段提到"隨著板塊的滑動和互相碰撞，大陸和海洋在慢慢改變著形狀"。提干符合文章本意，所以選擇 A。

18 C 文章第二段提到了地球這顆行星慢慢冷卻后，它的地殼慢慢形成移動的板塊，并沒有提及地球在冷卻后慢慢形成。題干的意思在文章中沒有體現(xiàn)，所以選擇 C。

19 B 文章第三段提到"他們發(fā)現(xiàn)的最新證據(jù)表明地殼的這種轉變至少是發(fā)生在 38 億年以前，這比之前的估計早了13 億年"。也就是之前的估計應為 25 億年前，題干"科學家曾 經(jīng)估計地殼的轉變發(fā)生在 30 億年前"不符合題意，所以選擇B。

20 C 文章第四段提到了 "堅硬的地亮形成之后……"，并沒有提及這個過程的時間。題干表達的意思沒有出現(xiàn)在文章中，所以選擇C。

21 A 文章最后一句話提到"上地殼帶開始形成于約3. 8 億年前"，所以題干表達的意思是正確的，選擇 A。

22 C 文章主題是研究者對地球的研究，并沒有提到上地殼帶是一個度假勝地。題干中的說法在文中沒有提及，所以選擇 C。

（責任編輯：vstara）

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