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 different 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. These 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.
“Color blindness” means           in Chinese.
A. 盲目        B. 无色      C 色盲    D 讨厌颜色
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

With the help of the “cones”, we can          .

A．tell different shapes	B．kill insets
C．see in the dark	D．tell orange from yellow

We can attract and kill mosquitoes by using a           light.

A．red

B．yellow

C．blue

D．green

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.