问题 问答题 简答题

牵引供电系统供电方式多种多样,那么它们的保护方式又有什么联系?

答案

参考答案:

我国电气化铁路发展时间虽然不长,但发展速度较快,新老设备、新旧线路同时并存,供电方式也有直供、BT、AT等多种方式,这就决定了不同的保护方式均有采用,但它们的共同特点是牵引网的保护大多以距离保护作为主保护,以电流保护作为后备或辅助保护。

阅读理解

阅读理解。

     One day,  Jack's  parents told him that  his grandpa would  retire(退休)  after working  for forty years.

Jack said in surprise, "I'm only seven, so it means Grandpa has been… er … A really long time!"

     His parents said, "Yes. That's why we are going to have a surprising party for him. "

     Jack loved his grandpa and wanted to do something special for him. He remembered the business card his grandpa had given him two years before. He knew that his  grandpa would no longer have the position(职位) on that card, so he decided to build a new one for his grandpa.

     When the big day came, Jack was ready.  But he didn't  want to put his gift together with  others'.  He

carried it around with him the whole evening.

     When all the other people left, he took his  grandpa's hand and brought him over to a chair and gave

him the gift.

     His grandpa smiled, "Well, it must be a beautiful gift. May I open it now?" "Sure!" Jack said excitedly.

     As Grandpa opened the gift, tears came into his eyes. Jack gave him the greatest gift he had ever got!

They were business cards with new position: FULL-TIME GRANDPA! Jack said, "Now your full-time

job is my grandpa!"

     Well, how much do I get paid?" his grandpa asked, smiling. "As many hugs as you want!" With these

words,  Jack  gave Grandpa a hug.  " Well,  I guess that means  I'm the richest man in the world! "  said

Grandpa.

1. Who was going to retire?

A. Jack's grandma.

B. Jack's grandpa.

C. Jack's mother.

D. Jack's father.

2.  Jack remembered __________ his grandpa had given him two years before.

A. the birthday card

B. the boy

C. the book

D. the business card

3.  What did Jack decide to do for his grandpa?

A. To build a new position for him.

B. To draw a picture for him.

C. To sing a song for him.

D. To buy a gift for him.

4. Which of the following is TRUE?

A. Jack was the first one to give his gift to his grandpa.

B. Jack was the last one to give his gift to his grandpa.

C. Jack gave his gift to his grandpa together with other people.

D. Jack gave his gift to his grandpa together with his parents.

5. Why were there tears in Grandpa's eyes?

A. Because he would lose his position.

B. Because he was not cared for.

C. Because he was moved by Jack's gift

D. Because he was unhappy.

选择题