Question

【题目】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】

试题分析：在南极洲冰块和海洋交汇的地方，生活着一种独特的小鱼。是什么原因能让这种鱼在其它鱼无法存活的地方生活呢？秘密就在它的血液里。

【1】细节理解题。根据倒数第二段的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，正是这种鱼的血液里有种特别的蛋白质，才使得它能够在如此的低温中生活。故选择C。

【2】词义判断题。根据上文可知这种小鱼体内的蛋白质使得它能够在低温中生存。再根据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。故这里的it指的就是前文的protein，选择B。

【3】推理判断题。根据前文的Because of its sugar content, 然后得出结论it is called a glycoprotein.所以这个词缀和sugar有关系，故选择A。

【4】主旨大意题。根据文章主题段第一段的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.可知本文讲述的是南极洲的一种小鱼，故选择B。