About ten men in every hundred suffer from color blindness in some way. Women are luckier; only about one in two hundred is affected in this matter. Perhaps, after all, it is safer to be driven by a woman!
There are different forms of color blindness. In some cases a man may not be able to see deep red. He may think that red, orange and yellow are all shadows of green. Sometimes a person cannot tell the difference between blue and green. In rare cases an unlucky man may see everything in shades of green － a strange world indeed.
Color blindness in human beings is a strange thing to explain. In a single eye there are millions of very small things called “cones”. These help us to see in a bright light and to tell difference between colors. There are also millions of “rods”, but these are used for seeing when it is near dark. They show us shape but no color.
Some insects have favorite colors. Mosquitoes prefer blue to yellow. A red light will not attract insects, but a blue lamp will. In a similar way human beings also have favorite colors. Yet we are lucky. With the aid of the cones in our eyes we can see many beautiful colors by day, and with the aid of the rods we can see shapes at night. One day we may even learn more about the invisible colors around us.
51. The passage is mainly about _____________.
A. color and its surprising effects. B. women being luckier than men
C. danger caused by color blindness D. color blindness
52. According to the passage, with the help of the “cones”, we can_______________.
A. tell different shapes B. see in a weak light
C. kill mosquitoes D. tell orange from yellow
53. Why do some people say it is safer to be driven by women?
A. Women are more careful.
B. There are fewer color-blind women
C. Women are fonder of driving than men.
D. Women are weaker but quicker in thinking.
54. Which of the statements about the color- blind is true?
A. Not all of them have the same problem in recognizing color.
B. None of them can see deep red.
C. None of them can tell the difference between blue and green.
D. All of them see everything in shades of green.
55. We can attract and kill mosquitoes by using a _____________.
A. red light B. yellow light C. blue light D. green light