问题 问答题 简答题

什么是沼气?

答案

参考答案:

沼气是有机物在隔绝空气和一定的温度、湿度、酸碱度等的条件下,经过沼气细菌的作用产生的一种可燃气体。由于这种气体最先是在沼泽中发现的,所以称为沼气。沼气的主要成分是甲烷、其余为二氧化碳、氧气、氮气和硫化氢。其中甲烷含量约为55%~70%,二氧化碳含量约为30%~45%。

单项选择题 A1型题
阅读理解

第三部分:阅读理解(共20小题,每题2分,满分40分)

阅读下列短文,从每题所给的四个选项(A、B、C和D)中,选出最佳选项。

One winter evening, a storekeeper was going to close up  his shop. Suddenly he saw Seth, a lazy, good – for – nothing fellow grasp a pound of fresh butter and hid it in his hat. No sooner had the storekeeper seen the act than he hit upon exactly the right revenge(报复). He would punish the thief, and satisfy his own appetite for fun.     

Seth had his hat on his head, and the butter in his hat. He was anxious to leave. However, the rightful owner of the butter offered him a cup of hot drink, took him by the shoulders and planted him in a seat close to the stove. The grocer filled in the stove as many sticks of wood as he could. Seth already could feel the butter settling down closer to his hair, so he jumped up, declaring that he must go. “Sit down; don’t be in such a hurry,” replied the grocer, pushing him back into the chair again.      

Streak after streak of the butter came pouring from under the poor man’s hat. The fun-loving grocer kept on putting wood into the stove. Then, as if surprised, he remarked, “You seem to be sweating as if you were warm! Let me put your hat away for you.”     

“No! ” exclaimed poor Seth at last, unable to stand it a moment longer. “ No, I must go; let me out.” A greasy (油腻的) waterfall of butter was now pouring down the poor man’s face and neck, dipping into his clothes, and trickling down his body into his boots. He was bathed in oil from head to toe. Just as Seth rushed out of the door, the grocer said , “ I believe the fun I’ve had out of you is worth the money, so I shan’t charge you for that pound of butter in your hat.”

56.Why did Seth put the butter in his hat?

A.Because he didn’t want to pay for it.

B.Because he just wanted to play a trick on the grocer.

C.Because he wanted to revenge himself on the grocer.

D.Because he had nowhere to put the butter but in the hat.

57.What is not the action that the grocer took as a revenge?

A.The grocer offered Seth a cup of hot drink.

B.The grocer offered to take off Seth’s hat.

C.The grocer overcharged Seth for the butter.

D.The grocer forced Seth to take a seat near the stove.

58.What was the purpose of the grocer’s hospitality(热情好客)?

A.He wanted to be kind to him.

B.He wanted to sell more of his goods.

C.He wanted to make friends with Seth

D.He wanted to take his revenge on Seth by making the butter in his hat melt.

59.What is the best title of the passage?

A.Great Fun                     B.The Right Revenge

C.A Fun-loving Grocer            D.A Foolish Customer