问题 单项选择题 A1型题

下列关于酶的叙述哪项是正确的()

A.酶的高度催化效率是因为分子中含有能传递氢原子、电子或其他化学基团的辅基或辅酶

B.酶的最适pH随反应时间缩短而升高

C.有些酶有同工酶,它们的理化性质不同是因为酶活性中心的结构不同

D.酶是高效催化剂,一般可用活力表示其含量

E.不同的酶催化不同的反应是因为其辅酶不同

答案

参考答案:D

阅读理解

第三部分 阅读理解(共15小题;每小题2分,满分30分)

阅读下列段文,从每题所给的四个选项(A、B、C和D)中,选出最佳选项。

A poor traveller stopped under the tree to eat the boiled rice and vegetables which he had brought with him. A few metres away, there was a small shop by the side of the road where a woman was frying (油炸)fish and selling it to travelers. The woman watched the poor traveler carefully, and when he finished his food and began to go, she shouted rudely, “You haven’t paid me for the fried fish!”

“But I have not had any fried fish!” he said.

“But everyone can see that you enjoyed the smell of my fried fish with your rice and vegetables,” said the woman, “If you had not smelled the fish, your meal would not have been so pleasant!”

Soon a crowd collected, and although they supported the poor traveler, they had to admit that wind was blowing from the shop to the place where he had eaten, and that it had carried the smell of the fried fish to him.

Finally, the woman took the poor traveler to a judge, who said, “The woman says that the traveler ate his meal with the smell of her fried fish. The traveler agrees that the wind was blowing from the woman’s shop to the place where he ate his rice and vegetables, and that it carried the smell of her fried fish to his nose while he was eating, so he must pay for it. What does your fried fish cost?” he asked the woman.

“Twenty-five cents a plate,” she answered, delighted.

“Then go outside together,” said the judge. “There the traveler must hold up a twenty-five-cent piece so that its shadow(影子)falls on the woman’s hand. The price of the smell of a plate of fried fish is the shadow of twenty-five cents.”

51. The traveler refused to pay the woman for the fried fish because       .

A. he was poor                                                 B. he was rude

C. he was supported by a crowd                  D. he hadn’t eaten her fried fish at all

52. Which of the following statements is true according to the passage?

A. The traveler bought the boiled rice and vegetables and ate them by the side of the road.

B. The judge had no idea what the woman meant.

C. In the fifth paragraph, the first “it” has the same meaning as the second “it”.

D. The woman got nothing but the shadow of twenty-five cents in the end.

53. The best title for the passage should be       .

A. The Smell and the Shadow

B. A Poor Traveler

C. A Rude Woman

D. A Woman and a Traveler

判断题