单选题 About ten men in every hundred suffer from colour blindness in some way; women are luckier with only about one in two hundred affected in this manner. There are different forms of colour blindness. A man may not be able to see deep red. He may think that red, orange and yellow are all shades 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.
In certain occupations colour blindness can be dangerous and candidates are tested most carefully. For example, when fighting at night, soldiers use lights of flares to signal to each other. A green light may mean "Advance" and a red light may mean "Danger! Keep back!" You can see what will happen if somebody thinks that red is green!
Colour 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 to see in a bright light and to tell the difference between colours. There are also millions of "rods", but these are used for seeing when it is nearly dark. They show us shape but not colour. Wait until it is dark tonight, then go outside. Look round you and try to see what colors you can recognize.
Birds and animals which hunt at night have eyes which contain few or no cones at all, so they cannot see colours. As far as we know, bats and adult owls cannot see colours at all but only light and dark shapes. Similarly, cats and dogs cannot see colours as well as we can.
Insects can see ultraviolet rays which are invisible to us, and some of them can even see X-rays. The wings of a moth may seem grey and dull to us, but to insects they may appear beautiful, showing colours which we cannot see. Scientists know that there are other colours around us which insects can see but which we cannot see. Some insects have favorite colours. Mosquitoes like blue, but do not like yellow. A red light will not attract insects but a blue lamp will.

单选题 Among people who suffer from colour blindness, ______.

A. some may see everything in shades of green
B. few can tell the difference between blue and green
C. few may think that red, orange and yellow are all shades of green
D. very few may think that everything in the world is in green

【正确答案】 D

【答案解析】[解析] 细节题。题干意为“在患有色盲症的人中”。A项意为“一些人可能看到的事物都是绿色的”；B项意为“少数人能区分蓝色和绿色”；C项意为“少数人会将红色、橙色和黄色都当做绿色”；D项意为“很少有人会认为世界上的所有事物都是绿色的”。根据题干线索词people who suffer from color blindness定位至第一段，根据该段第三至第六句可以推断，A、B、C项中对色盲人数多少的限定词some或few不够准确，D项与第六句意思一致，故D为正确答案。

单选题 When millions of rods in our eyes are at work in darkness, we can see ______.

A. colours only
B. shapes and colours
C. shapes only
D. darkness only

【正确答案】 C

【答案解析】[解析] 细节题。题干意为“当我们眼睛中数以百万的视杆细胞在黑暗情况下起作用时，我们能识别”。A项意为“只有颜色”；B项意为“形状和颜色”；C项意为“只有形状”；D项意为“只有黑暗”。根据题干线索词millions of rods和in darkness定位至第三段，其中倒数第三句提到They show us shape but not colour(他们可以使我们看得到事物的形状，而看不清其颜色)，这里的they即指millions of rods。由此推知，C为正确答案。

单选题 According to the passage, bats and adult owls cannot see colours because ______.

A. they hunt at night
B. they cannot see light
C. they have no cones and rods
D. they have no cones

【正确答案】 D

【答案解析】[解析] 细节题。题干意为“根据文章，蝙蝠和成年猫头鹰不能识别颜色是因为”。A项意为“它们在夜间狩猎”；B项意为“它们不能识别光”；C项意为“它们没有视锥细胞和视杆细胞”；D项意为“它们没有视锥细胞”。根据题干线索词bats and adult owls定位至第四段第二句。该句提到，蝙蝠和成年猫头鹰不能识别色彩，只能识别光和黑暗中事物的形状。其原因在该段第一句提到，即夜间进行捕猎的动物眼睛中含有很少或根本不含有视锥细胞。由此推断，D为正确答案。

单选题 According to the passage, dogs and cats ______.

A. as well as human beings can not see some colours
B. have fewer cones than human beings
C. have fewer rods than human beings
D. can see colours as well as human beings

【正确答案】 B

【答案解析】[解析] 细节题。题干意为“根据原文，狗和猫”。A项意为“和人类一样不能识别一些颜色”；B项意为“拥有的视锥细胞比人类少”；C项意为“拥有的视杆细胞比人类少”；D项意为“和人类一样能识别很多颜色”。根据题干线索词dogs and cats定位至第四段第三句，句中提到，狗和猫不能像人类一样能够很好地识别一些颜色，即狗和猫识别颜色的能力不如人类。而该段第一句提到原因，即不能识别颜色是因为动物眼睛中含有的视锥细胞少。由此推知，狗和猫的视锥细胞不如人类多。因此，B为正确答案。这里需要注意as well as在第四段第四句和D项中意思是“和……一样好”，是比较级的as...as形式，而在A项中作为短语，意思则是“和……一样；也……”。

单选题 Which of the following is not true about insects?

A. Insects can see more colours than human beings.
B. Insects can see ultraviolet rays which are invisible to men.
C. All insects have their favorite colours.
D. The world is more colorful to insects than to human beings.

【正确答案】 C

【答案解析】[解析] 是非细节题。题干意为：“关于昆虫的叙述，下列哪项是不正确的?”A项意为“昆虫比人类能识别更多的颜色”；B项意为“昆虫能识别紫外线，而人类不能”；C项意为“所有的昆虫都有它们喜欢的颜色”；D项意为“世界在昆虫眼中要比在人类眼中更加色彩斑斓”。根据题干线索词insects定位至最后一段，由该段第一句可推知B项为正确论述；由该段第二句可推知A、D项为正确论述；而根据该段倒数第三句Some insects have favorite colours(一些昆虫有自己喜欢的颜色)可推知，C项论述过于绝对，属于错误论述。因此，C为正确答案。