问题 问答题 简答题

屏蔽橡套电缆与普通橡套电缆有什么不同?

答案

参考答案:屏蔽橡套电缆在构造上与普通电缆基本相同,其不同点是在主芯线上先绕包聚脂薄膜或其他非吸湿性材料,在内护套外再加包一层半导电胶布带(国外也有用尼龙绳钢丝组成的半导电编织带)作为分相屏蔽层;接地芯线挤包半导电橡皮后,外面再绕包一层半导电胶布带。如是四芯电缆,其中心的线芯也应是半导电橡皮;如是七芯电缆,接地芯线放在电缆中心,3根控制芯线绞合在一起,并在外面重绕包聚酯萍膜,然后再挤包填充绝缘橡皮,外面再绕包半导电胶布带。每根主芯线的屏蔽层的过渡电阻,常温下大于3kΩ。

阅读理解

阅读理解。

    Today, roller-skating is easy and fun. But a long time ago,it wasn't easy at all. Before 1750, no one had

any ideas of roller-skating. That changed because of a man named Joseph Merlin. He liked to make things

and play the violin in his free time. Joseph Merlin was a man of ideas and dreams. People called him a

dreamer.

    One day he was invited to a party. He was pleased and a little excited. As the day of the party came near,

Merlin began to think how to make an amazing entrance at the party. He had an idea. He thought everyone

at the party would show much interest if he could skate into the room.

     Merlin tried different ways to make himself roll. Finally, he decided to put two wheels under each shoe.

These were the first roller skates. Merlin was very proud of his invention and dreamed of arriving at the party

on wheels while playing the violin.

     On the night of the party Merlin rolled into the room playing his violin. Everyone was very surprised to

see him. There was just one problem. Merlin had no way to stop his roller skates. He rolled on and on.

Suddenly, he ran into a huge minor that was hanging on the wall. The mirror fell down, breaking into pieces.

Merlin's idea was so good that nobody forget his special entrance for a long time. But could he find out a

way to stop his roller skates?

1. The passage is mainly about ______. [ ]

A. a careless man

B. a wonderful dream

C. the birth of roller skates

D. the birth of violins

2. People thought Merlin was a dreamer because he ______. [ ]

A. dreamed day and night

B. 1iked making things

C. was an interesting man

D. was full of strange ideas

3. Merlin wanted to______, so he put wheels under his shoes. [ ]

A. play the violin well

B. arrive at the party sooner

C. be taller than the others

D. surprise the people at the party

4. What did the writer want to tell us in the last paragraph? [ ]

A. Merlin made a lot of trouble.

B. Roller skates should be improved.

C. The people were angry with Merlin.

D. Merlin was strong enough to break the mirror into pieces.

5. Which of the following is true? [ ]

A. Nothing happened to Merlin at the party.

B. Merlin made a surprising entrance that day.

C. No one noticed Merlin when he entered the room.

D. Merlin couldn't sleep well because he dreamed a lot.

阅读理解

     Nikos Kaklamanakis will go down as one of the best windsurfing athletes the world has ever known.

Nikos was the winner of the Gold Medal in the 1996 Olympic Games in Atlanta. Another three athletes

also won gold medals for Greece. This marked an important stage for Greece, since it was the first time in

the country's history to bring home four gold medals in a single Olympic Games.

     According to Nikos Kaklamanakis' official website, he says his "entire life is a journey. Set a goal, and

give my heart to achieve it. "He further notes that he is not afraid of challenges, nor does he ever want

challenges to end. Particularly impressive about Nikos is that throughout his life, he has spent more time

at sea than on land.

     Called by many journalists as the "gios tou anemou", which means "the son of wind," Nikos was

honored as the silver medalist at the 2004 Summer Olympic Games in Athens. He also won the gold

medals in the Mistral World Championships three times, in 1996, 2000 and 2001 separately. Nikos

received praise from the Greek Sports Press Association.

     At the 1996 Olympic Games in Atlanta, Kaklamanakis served as the flagbearer for Greece at the

closing ceremony. Lastly, serving as a torchbearer, Nikos was the first athlete to enter the Olympic

stadium in the opening ceremony of the 2000 Olympic Games. Nikos received the greatest honor of

lighting the Olympic torch in the opening ceremony of the 2004 Summer Olympic Games that were

held in Athens, Greece.

     At 42, Kaklamanakis shows no signs of slowing down. On August 31, 2009 Nikos won another

world championship gold medal. This shows greatly that Nikos is like "fine wine". He only gets better

with age! Generally Nikos is a man with strength and willpower. He is living proof that nothing is

impossible as long as you stay focused and give your heart and soul to achieve your goal.

1. What can we learn about Nikos Kaklamanakis from the passage?

A. He is a swimming athlete and practices hard.

B. He is the best windsurfing athlete in the world.

C. He has won three medals altogether till now.

D. He brought great honor to his motherland in 1996.

2. What makes people admire Nikos is that ________.

A. he practices very hard

B. he sets a very high goal

C. he fears no challenges

D. he is "the son of wind"

3. Which gives Nikos the highest honor according to the author?

A. His serving as a torchbearer.

B. His serving as the flagbearer.

C. His lighting the Olympic torch.

D. His being praised by radio.

4. It can be inferred that ________.

A. his courage disappears with age

B. the older he is,the better he performs

C. he has fallen behind other athletes now

D. he is in poor health at present

5. What is the secret of Nikos Kaklamanakis' success?

A. Working hard to realize the goal he sets.

B. The support from his friends and family.

C. The love for windsurfing.

D. Paying attention to his goal all the time.

6. 用30词左右概括文章大意

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