71230999人四舍五入到万位是（ ） A．7123万人 B．7124万人 C．71

阅读理解。

     Roger, a young man from China, has taught Chinese in a primary school in England for 3 years. A lot of

children like his class and he enjoys teaching them very much. All the pupils are quite interested in what Roger

teaches them. They learn quickly and do everything carefully.

     One day he said to the children,"People in a lot of Asian countries wear white clothes at funerals (葬礼),

but people in America and in Europe wear white in the weddings because white means purity and happiness.

What colour does an English woman wear when she gets married?"

     Mary said,"White, sir, because she is happy." "That is good, Mary," Roger said."You are quite right. She

wears white because she is happy."

     But then one boy in the class put up his hand."Yes, Dick?" Roger said, "Do you have a question?" "Yes,"

     Dick said."Why do men wear black in our country when they get married, sir?"

1. What does Roger do?

A. He teaches English in China

B. He is a Chinese teacher in China

C. He teaches Chinese in England

D. He teaches English in England

2. Roger enjoys teaching his pupils because _______.

A. they are his own children

B. they are clever and careful

C. they are lovely

D. they are polite and helpful

3. An English woman wears white clothes _______.

A. when she gets married

B. when she is worried

C. when she is sad

D. when she is a funeral

4. What colour do men in England wear when they get married?

A. White

B. Black

C. Red

D. Green

5. Which of the following is true?

A. Roger dislikes teaching the children.

B. Dick was a slow girl.

C. People in England wear white when they get married.

D. Dick, a clever boy, liked asking questions.

矩形的两条对角线的夹角为60°，较短的边长为12cm，则对角线长为______cm．

β-TG和PF₄增高常见于（）。

A.高凝状态

B.血栓性疾病

C.血小板减少症

D.vWD

E.血小板无力症

在石灰岩地块为什么会出现仙境般的岩洞？（请用文字及反应方程式加以说明）

铝管支架间距需比钢管密一些，热轧管按同管径同壁厚的碳素钢管支架间距的( )取用。

A．1/2

B．1/3

C．2/3

D．3/4