Question

【題目】Far from the land of Antarctica, a huge shelf of ice meets the ocean. At the underside of the shelf there lives a small fish, the Antarctic cod.

For forty years scientists have been curious about that fish. How does it live where most fish would freeze to death? It must have some secret. The Antarctic is not a comfortable place to work and research has been slow. Now it seems we have an answer.

Research was begun by cutting holes in the ice and catching the fish. Scientists studied the fish’s blood and measured its freezing point.

The fish were taken from seawater that had a temperature of -1.88°C and many tiny pieces of ice floating in it. The blood of the fish did not begin to freeze until its temperature was lowered to -2.05°C. That small difference is enough for the fish to live at the freezing temperature of the ice-salt mixture.

The scientists’ next research job was clear: Find out what in the fish’s blood kept it from freezing. Their search led to some really strange thing made up of a protein never before seen in the blood of a fish. When it was removed, the blood froze at seawater temperature. When it was put back, the blood again had its antifreeze quality and a lowered freezing point.

Study showed that it is an unusual kind of protein. It has many small sugar molecules (分子) held in special positions within each big protein molecule. Because of its sugar content, it is called a glycoprotein. So it has come to be called the antifreeze fish glycoprotein, or AFGP.

【1】Why can the Antarctic cod live at the freezing temperature?

A. The seawater has a temperature of -1.88°C.

B. It loves to live in the ice-salt mixture

C. A special protein keeps it from freezing.

D. Its blood has a temperature lower than -2.05°C.

【2】What does the underlined word “it” in Paragraph 5 refer to?

A. A type of ice-salt mixture.

B. A newly found protein.

C. Fish blood.

D. Sugar molecule.

【3】What does “glyco-” in the underlined word “glycoprotein” in the last paragraph mean?

A. sugar B. ice C. blood D. molecule

【4】What is the best title of this passage?

A. Discovery of the AFGP.

B. A special fish living in Antarctica.

C. The ice shelf around Antarctica.

D. Protection of the Antarctic cod.

Answer 1

【答案】

【1】C

【2】B

【3】A

【4】B

【解析】

試題分析：在南極洲冰塊和海洋交匯的地方，生活著一種獨特的小魚。是什么原因能讓這種魚在其它魚無法存活的地方生活呢？秘密就在它的血液里。

【1】細節(jié)理解題。根據(jù)倒數(shù)第二段的Find out what in the fish’s blood kept it from freezing. Their search led to some really strange thing made up of a protein never before seen in the blood of a fish.可知，正是這種魚的血液里有種特別的蛋白質，才使得它能夠在如此的低溫中生活。故選擇C。

【2】詞義判斷題。根據(jù)上文可知這種小魚體內的蛋白質使得它能夠在低溫中生存。再根據(jù)When it was removed, the blood froze at seawater temperature. When it was put back, the blood again had its antifreeze quality and a lowered freezing point.可知it被拿走后，血液就凝固了。故這里的it指的就是前文的protein，選擇B。

【3】推理判斷題。根據(jù)前文的Because of its sugar content, 然后得出結論it is called a glycoprotein.所以這個詞綴和sugar有關系，故選擇A。

【4】主旨大意題。根據(jù)文章主題段第一段的Far from the land of Antarctica, a huge shelf of ice meets the ocean. At the underside of the shelf there lives a small fish, the Antarctic cod.可知本文講述的是南極洲的一種小魚，故選擇B。