玉米从种到收共分（）个生长时期。A、10 B、11 C、12 D、13

阅读理解。

     About ten men in every hundred have the trouble of color blindness in some way. Women are luckier,

only about one in two hundred is affected (感染) in this matter. Perhaps, after all, it is safer to be driven

by a woman.

    There are different kinds of color blindness. For example, a man cannot see deep red. He may think

that red, orange and yellow are all shades (影子)of green. Sometimes a person can't tell the difference

between blue and green. Only a few unlucky men may see everything in shades of green-a strange world

indeed.

    Color blindness in human beings is a difficult thing to explain. In only one eye there are millions of very

small things called "cones (锥状细胞)". These help us to see in the bright light and to tell differences

between colors. There are also millions of  "rods ( 杆状细胞)", but these are used for seeing when it is

nearly dark. They show us shapes but not colors.

    Some insects have favorite colors. Mosquitoes (蚊子) like blue but do not like yellow. A red light

will not attract insects, but a blue light will. Human beings also have favorite colors. Yet we are lucky.

With the help of the cones in our eyes, we can see many beautiful colors by day, and with the help of

the rods we can see shapes at night.

1. "Color blindness" means "______" in Chinese.

A. 盲目    

B. 无色    

C. 色盲    

D. 讨厌颜色

2. Some people say it's safer to be driven by women because ______.

A. women drive more carefully

B. women are better at driving than men

C. women can see things more clearly

D. there are fewer color-blind women

3. With the help of the "cones", we can ______.

A. tell different shapes  

B. kill insects

C. see in the dark    

D. tell orange from yellow

4. We can attract and kill mosquitoes by using a ______ light.

A. red    

B. yellow    

C. blue    

D. green

5. Which of the following sentences about color blindness is TRUE?

A. None of men can see deep red.

B. Not all of men have the same problem in recognizing colors.

C. None of men can tell the difference between blue and green.

D. All of men see everything in shades of green.

青蛙既可以生活在水中又可以生活在陆地上，因此称为两栖动物。            （    ）

下列不是带状疱疹分型的是

A．无疹型

B．出血疹

C．局限型

D．坏血型

E．泛发型

钢管焊道有1处手工补焊，成鱼脊状，最有可能发生的3PE焊道缺陷是（）。

A.开裂

B.减薄

C.局部空腔

D.以上三者均是

为了预防高血压，一般成年人每天吃盐不能超过多少克？（）

A、2克；

B、6克；

C、9克；

D、12克；