在距地面高为h的光滑水平桌面上，一个轻弹簧左端固定，右端紧挨一质量为m的小球。用

I have returned to my hometown after I was away ten years ago. So many things have changed around here. It has become better and better. When I left here, there was a small pool on the right of my house. Now the pool has gone and people have built a large shopping mall(商场) there.

The biggest changes have taken place in the center of the city. There are sidewalks on both sides of the street. You can see a street center with so many tall buildings around. You can’t drive there any more because no vehicle is allowed to pass there. A European-style fountain(喷泉) has been built in the street center garden.

There used to be an old school near my house. I spent my five years studying there. There was a small payground in front of the school. But now what I can see are five tall buildings standing there. There are two big classroom buildings and a library. A new post office has also been built just across from the new school.

小题1:I have been away from my hometown for ________.

A．ten months

B．one year

C．five years

D．ten years小题2:On the right of my house, there was a _________ ten years ago.

A．library

B．garden

C．supermarket

D．pool小题3:No vehicle is allowed to pass the _________.

A．center of the city

B．old school

C．street center

D．playground小题4:Which of the following is WRONG(错的)?

A．A fountain is in the street center garden.

B．Now there is an old school near my house.

C．There are two big classroom buildings and a library in the new school.

D．There is a post office across from the school.小题5:What’s the best title for the passage?

A．Great Changes in My Hometown.

B．A Wonderful Place

C．What a Nice Town

D．My School.

抽绎

《周易》中的（）倡导国民理解自然和人文。

A、贲卦

B、乾卦

C、井卦

D、坤卦

甲亢最具有诊断意义的体征是

A．心率加快，第一心音亢进
B．弥漫性甲状腺肿伴血管杂音
C．突眼
D．胫骨前黏液水肿
E．脉压差大伴周围血管征

RO进水要经过哪些预处理？