People who cannot tell all colors apart are said to be color-blind. Most color-blind peopl

People who cannot tell all colors apart are said to be color-blind. Most color-blind people can see yellows and blues, but confuse reds with green. It is very rare for a person to be blind to all colors, but they may see everything in shades of black, white and gray.
It is interesting to point out that many color-blind people don’t even realize that they are color-blind, they don’t know that the colors they are seeing and naming are not the actual colors that people with normal vision can see. This can be dangerous when a color-blind person confuses the red and green of a traffic light.
Color blindness is thought to be inherited（遗传）and although doctors have tested color blindness, there is no cure to treatment for it.
【小题1】There are four cards here, and each has two colors. Which card’s colors do you think a color-blind person can tell correctly?A．Red, GreenB．Green, YellowC．Red, BrownD．Brown, Yellow【小题2】A color-blind person    .A．always knows how color-blind he isB．often gives the wrong name of colorsC．see everything as the same colorD．can hardly see something of strong colors【小题3】It’s especially dangerous for a color-blind person to cross a street when    A．it is crowdedB．it is a dark nightC．there are no traffic lights at the cross of the streets D．the traffic light turns red【小题4】A person who is color-blind is believed to have something to do with    .A．his old ageB．his poor eyesightC．his parents or grandparentsD．his living condition【小题5】Up to now, doctors    .A．have found a way to prevent a person from getting color-blindB．have found a way to free a person from his color blindnessC．have been able to tell whether a person is color-blind or notD．have made it quite clear the cause of color blindnessD