120阀在作用原理上属二压力机构直接作用式。

Dear Earthmen(地球人)，

I enjoy my stay on your interesting planet(星球).

I think I know the life on Earth now and I would like to tell you my ideas.

First of all you live in boxes. Every morning you leave your boxes and get into smaller boxes on wheels(轮子). All these small boxes run around and around, and finally stop to rest. You leave these boxes on wheels and go to very large tall boxes.

After resting all day, you get back in your little boxes. There you sit and look at very small glowing boxes with moving pictures in them.

There is only one thing I don’t know. Some angry boys fought for a little round (圆的) ball. Everyone shouted(大声喊) but they kept fighting. They were angry, because they had to stay in boxes all day, I think.

Thank you for this chance(机会) to get to know you.

Yours,

The man from Mars(火星)

小题1:How many kinds of “boxes” does the man from Mars tell us？

A．Two

B．Three

C．Four

D．Five小题2:What do the boxes on wheels refer to(指的是)?

A．Houses

B．Buildings

C．Cars

D．TVs小题3:What does the word “glowing” mean in Chinese?

A．发光的

B．开心的

C．漂亮的

D．黑暗的小题4:What’s the main(主要的) idea of the letter？

A．To say goodbye to the Earthmen

B．To tell the Earthmen what the Earth is like.

C．To tell the Earthmen he doesn’t like the Earth.

D．To tell the Earthmen he is leaving the Earth soon.

Everyone ______him, because he is friendly.

A．like

B．likes

C．to like

D．liking

下列离子方程式书写正确的是

[     ]

A．氢氧化钡与HCl：2H⁺+2OH^-=2H₂O

B．石灰石与醋酸：CaCO₃+2H⁺=Ca²⁺+CO₂↑+H₂O

C．铁与稀H₂SO₄：2Fe+6H⁺=2Fe³⁺+3H₂↑

D．氢氧化钠与CuSO₄：2OH^-+Cu²⁺=Cu(OH)₂↓

下列属于卵生动物的是                                  （    ）

A．斑点狗

B．家兔

C．波斯猫

D．蝴蝶

为便于管理，“应收账款”、“应付账款”的明细账必须采取多栏式明细分类账格式。 ( )