问题 问答题 简答题

为什么给汽封时必须先盘车?

答案

参考答案:

如果不盘车,透平的转子不动,汽封的蒸汽就会使转子后部受热弯曲,而造成不良影响和严重后果,盘车能使转子受热均匀,没有冷热不均匀的应力产生。

口语交际,情景问答题
完形填空

Have you ever wished that you could make your little sister’s teddy bear talk to her? Or have you ever wanted to bring a puppet (木偶) to life? If so, you may be interested in learning the art of ventriloquism (腹语术). A ventriloquist can make an ordinary object seem to be alive by giving it a personality, movement, and speech.

Your object can be a puppet, or a doll. Give your new “friend” a name, and then decide on the personality that he will have. The next step is to give your friend movements that agree with the personality you have chosen.

Now you can learn to make your “friend” talk. A ventriloquist will control his mouth and lips so that it will appear that his voice is coming from the object he is using. This will take practice, but you can do it.

First, decide on a voice that is different from your own. It could be higher or lower than yours, or could even have a special accent. Then, find a clean teaspoon and hold the handle between your front teeth. Now, using the voice you created for your friend and holding the handle of the teaspoon tightly between your teeth, look into a mirror and talk. Practicing with the spoon in your mouth will help you learn to keep your mouth from moving. Now try telling a joke in your normal voice and have your friend speak in his voice. Practice those words until you can say them without your lips moving at all.

Ventriloquism is fun. It also requires hard work to become good at it. The most important thing to do is practice. But if you are willing to take the time to give your friend an interesting personality, to practice lively movements, and to work on good mouth control, then you will be well on your way to becoming a ventriloquist!

小题1:According to the text, a ventriloquist           .

A.is a person who can make puppets

B.needs to work with another person

C.can speak without using his mouth

D.can make an object seem to speak小题2:You need to hold the handle of a teaspoon between your front teeth so that           .

A.your voice will change

B.your mouth won’t move

C.you can look humorous

D.you can feel your mouth’s movements小题3:If you want to be good at ventriloquism, you         .

A.need to spend much time practicing

B.must learn from famous ventriloquists

C.should learn at least one special accent

D.must have a great doll to practice with 小题4:What would be the best title for the text?

A.How to tell jokes

B.How to make puppets

C.Secrets of ventriloquism

D.Tips on making friends