问题 多项选择题

以下属于线控式探测器的有()。

A.主动式红外入侵探测器

B.长导电体断裂原理探测器

C.微波和被动红外复合入侵探测器

D.室内用多普勒微波探测器

E.短导电体的断裂原理探测器

答案

参考答案:A, B, C, D, E

完形填空

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

Richard’s father died when he was five. Later on he lost his mother. An old woman felt sorry for the poor boy and often helped him. Of course he had no money to go to school. He had to work for a rich farmer. The man paid him nothing except food and clothes.__ 小题1:_ He found some old books near the school and taught himself to read and write.

_小题2:__It connected the village and the town. One morning people found there was a big stone on it. It stopped them from going to town. They had to move it away, or they had to cross the mountain if they had something to do in the town. But the stone weighed thirty tons at least and the strongest young men couldn’t do that.  _小题3:__

Richard looked at it carefully for a while and said, “I have a way to move it away.” But few men believed him. __小题4:__ Night fell and people went home. Only the boy stayed there. To their surprise, the villagers found the stone was gone the next morning. They didn’t know which spirit had moved it away.__ 小题5:__

“How could he?” the rich farmer called out. “He’s only fifteen! He couldn’t move it at all!”

“He dug a big hole beside the stone”, said the old woman, “And then he could easily push it into the hole!”

Looking at each other, the farmers couldn’t say a word.

A.The old woman said Richard had done it all.

B.There seemed to be nothing strange in village.

C.There was a narrow path between two mountains.

D.They discussed for a long time, but nobody knew what to do.E. The boy hoped he could do something for the villagers some day.

F. Some farmers even laughed at the boy.

G. But the boy didn’t lose heart.

单项选择题