正四面体ABCD的外接球的球心为0,E是BC的中点，则直线OE与平面BCD所成角

阅读理解

       Everyone has his own way of saying things and his own special expressions. Many American

everyday expressions are from colors.

       Red is a hot color. Americans often use it to express "heat". They may say they are red hot about

something unfair. When they're red hot they are very angry about something. Fast loud music is popular

with many people. They may say the music is red hot.

       Pink is a lighter kind of red. People sometimes say they're in the pink when they're in good health.

The expression was first used in America at the beginning of the 20th century. It probably came from

many babies who were born with a nice pink color showing good health.

       Blue is a cool color. The traditional blues music in the USA is the opposite of(与……相反) red

hot music. Blues is slow and sad.

       The color green is natural for trees and grass. But it's an unnatural color for humans. A person who

has a sick feeling stomach may say he feels a little green. A passenger on a boat who is feeling very sick

from high waves may look very green.

1. What does the expression "be red hot about" mean?

A. Be very angry.          

B. Be unfair.

C. Be happy.              

D. Be very popular.

2. Why do Americans use the color pink to express the meaning of healthy?

A. Because the color pink is lighter than the color red.

B. Because their ancestors(祖先) did so many years ago.

C. Because many healthy babies were born with the pink color.

D. Because it's a traditional expression.

3. What's the opposite of the red hot music?

A. Fast music.            

B. Loud music.

C. Blues music.            

D. Country music.

4. How many colors are mentioned in the passage?

A. 3.        

B. 4.        

C. 5.        

D. 6.

5. Which is the BEST title for the passage?

A. Different Colors

B. Strange Expressions

C. Colorful World

D. Feelings Behind Color Words

在下列物质：①空气、②水、③汞、④液氧、⑤氯酸钾、⑥氦气、⑦石灰水、⑧氧化铜、⑨硫酸锌．用序号回答下列问题：

（1）属于混合物的是______．

（2）属于单质的有______，其中是金属的是______．

（3）属于化合物的是______，其中是氧化物的是______．

作为中国古典小说颠峰的作品, 揭示清朝封建制度走向衰落的小说是（ ）

A．《红楼梦》

B．《西游记》

C．《三国演义》

D．《水浒传》

产权比率为3/5，则权益乘数为( )。

A．4/5

B．8/5

C．5/4

D．5/8

1211灭火器仅适用于扑灭易燃、可燃气体或液体，不适用于扑灭一般易燃固体物质的火灾。