问题 单项选择题

电动机、变压器、油机、机房机柜的外壳接地属于()。

A、接零

B、工作接地

C、保护接地

D、重复接地

答案

参考答案:C

阅读理解

根据短文,补全文后的句子。

     There was a pilot (飞行员) and four people in a small plane. Suddenly there was something wrong

 with the machine while it was flying in the air.  The Smoke was everywhere in the plane.  The pilot told

 the people there were only four parachutes (降落伞).  They all became worried and started to make

  excuses.

    "I must go and mend the machine," said the pilot, taking one of the parachutes. There was nothing he

 could do so he jumped out.

    The first person stood up.   "I'm a doctor," he said. "I help people live longer and I save lives." He also

 took a parachute and jumped out.

    The next person said, "I must have a parachute.  I'm a very clever person.  I have to take part in an

 important sports match.  I know I'll win the game because I'll be the cleverest person there."  He picked

 up a pack and jumped out.

     Two men were left: an old businessman and a young mountain climber.  By this time the plane was

 going down fast. The businessman said, "Young man, I'm old but you're still young. You take the last

 parachute." The young mountain climber smiled. "Don't worry," he said. "We can both jump safely

 because there are still two parachutes.  Just now the clever person jumped out with my back pack

 (背包)."

1. All the people became worried because _____.

2. The "clever" man jumped out with _____.

3. All the People only thought of themselves except _____

4. From the story we know that ______ would be dead.

5. _____ was a kind-hearted man.

单项选择题