问题 问答题 计算题

一泵低位布置,若水池液面h高于泵中心5m,求泵进口静压力。假设水池中是清水且密度ρ为1000kg/m3,当地大气压力pa=100kPa。

答案

参考答案:

泵入口静压力

p=pa+ρgh

 =100×103+1000×9.8×5

=149000(PA.=0.149(MPA.

泵入口静压力为149MPa。

填空题
阅读理解

Narcissus was a beautiful looking boy. He had long, flowing, blond hair, beautiful, bright, blue eyes and even, white teeth. Many young ladies fell in love with him including the nymph(女神): Echo.

Nymphs were lively spirits who lived near streams and lakes and protected trees in the forest. Echo had upset the Queen of the Gods; Hera. As a punishment Hera made Echo unable to speak except to repeat the last three words of the person she was talking to.

Poor Echo fell in love with Narcissus but could never tell him how she felt. Narcissus teased her and she ran away with tears pouring down her face. Aphrodite, the goddess of love saw what happened and decided to punish Narcissus. As he came to a pool of water Narcissus saw his reflection (影子)and fell in love with the vision he saw. It was of course his own reflection.

Poor Narcissus watched his own reflection, every time he tried to touch the face of the vision he loved it broke up on the shimmering surface of the water. Narcissus stopped eating, lost his beautiful looks and desired to get his love. In the end he anguished gradually and died.

Aphrodite took pity on him and made a flower grow in his place on the bank of the lake. Narcissus flowers (水仙花) can be found to this day growing wherever you can find water and trees.  

小题1:Echo fell in love with Narcissus because_________.

A.Narcissus was good-looking.

B.Echo was a lively spirit

C.Narcissus loved her, too.

D.Echo took pity on Narcissus小题2: Why did Aphrodite, the goddess of love, punish Narcissus?

A.Aphrodite envied Echo because she loved Narcissus

B.She thought Narcissus didn’t respect and made Echo sad.

C.Narcissus fell in love with the vision, not Echo.

D.Echo was trapped in love and didn’t protect trees in the forest any longer.小题3:What does the underlined word “anguished” in the fourth paragraph mean?

A.become increasingly thin and weak

B.become very hungry

C.become very fat

D.become out of mind小题4:What is the main purpose of writing the passage?

A.To tell people a sad love story

B.To tell people how Narcissus flowers came

C.To tell the true meaning of beauty and ugliness

D.To tell people not affect others’ love