问题 问答题 简答题

启动抽气器主要任务?主抽气器主要任务?

答案

参考答案:

(1)启动抽气器的主要任务是:在汽轮机启动前和启动过程中抽出汽轮机本体和凝汽器内的大量空气,迅速建立必要的真空,以便汽轮机进行启动。

(2)主抽气器的主要任务是:在汽轮机正常运行中,将凝汽器内的不凝结气体抽出,以保持凝汽器的真空。

阅读理解

阅读理解

      Where we live, on the eastern shore of Maryland, the gentle waters run in and out like fingers slimming at the tips.

     The Canada geese know this place, as do the white swans and the ducks.In autumn, they come home

for the winter.Once or twice each year, snow and frozen rain move into the area.When this happens, if the river is at its narrowest, there is a freeze which hardens the water to ice.

     One morning, a friend of mine set the breakfast table beside the huge window, which overlooked the

Tred Avon River.Suddenly she leaned forward and cried out, "There is a goose out there."

     We saw the figure of a large Canada goose, very still, its wings folded tight to its sides, its feet frozen

into the ice.

     Then from the dark skies, she saw a line of swans.They floated from the top of the sky downward

and at last landed on the ice.My friend was on her feet now, with one hand against her mouth, unbelieving.As the swans surrounded the frozen goose, she feared that life it still had might be pecked(啄) out by

those great swan bills.

     Instead, those bills began to work on the ice.The long necks were lifted and curved down, again and

again.It went on for a long time.At last, the goose's head was lifted.Its body was pulled.Then the goose

was free and stood on the ice.And the swans stood in the air watching.Then, as if it had cried, "I cannot

fly."Four of the swans came down around it.Their powerful beaks chipped off the ice held in the feathers.

Slowly, the goose spread its wings as far as they would go, and moved slowly into the sky.

     This is a true story.I just think of it in the bad moment, and from it comes only one hopeful question:If

so for birds, why not for man?

1. Which would be the best title for the passage?

A. Why Not for Man?   

B. Graceful Swans

C. Swans' Brave Act    

D. I Just Couldn't Believe It!

2. What happened to the Canada goose?

A. It was deserted by other geese.    

B. It was stuck in the ice.

C. It was wounded and couldn't fly.  

D. It was lost in the water.

3. At first the author's friend was worried that________.

A. the swans would not help the Canada goose

B. she didn't care about this matter any more

C. the swans wouldn't identify with the Canada goose

D. the swans would peck the Canada goose to death

4. What did the swans do when they saw the Canada goose couldn't fly?

A. They chipped off the ice held in its feathers.

B. They waited patiently for the ice held in its feathers to melt.

C. They came down and lifted it up to the sky together.

D. They stayed with it and protected it.

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