The Peppered Moth, a kind of insect, is found in England. It is light brown in color and

The Peppered Moth, a kind of insect, is found in England. It is light brown in color and likes to settle on trees which are also light brown. This makes the moth difficult to be seen and birds are less likely to notice and eat it.
But with the development of industry, smoke from factories began to reach the trees where the moth settled. It made the trees blacker. Then something very strange took place: in industrial areas, the Peppered Moth began to change color. It became darker as well. Although the change took several years, some scientists soon noticed that newly-born moths were a little darker than usual.
A scientist called Kettle Well decided to make a careful study of this. He marked some of the light moths and some of the darker ones, and set them free in the woods near Birmingham, an industrial city. Later he retarget as many the marked moths as possible ( The result was given in the chart ).
Kettle Well’s research was done in the early 1950s. Soon afterwards Britain introduced new laws to reduce smoke and factory pollution.
Can you imagine what would happen to the Peppered Moth as the air became cleaner again? 
 
light moths
darker moths
Moths set free
201
601
Moths recaught
34 ( 16%)
206 ( 34%)
1. The trees where the Peppered Moth settled changed their color because     .
A. the Peppered Moth changed its color
B. the Peppered Moth couldn’t be easily found on them
C. industry in England developed quickly 
D. the smoke from factories polluted them
2. The Peppered Moth began to change its color in industrial areas because       .
A. it changed its color all the time   
B. it was fond of the color of its living place
C. it had to protect itself by doing so 
D. it was a special sort of insect
3. From the results of Kettle Well’s research, we can see that     .
A. many more of the light moths were killed or eaten
B. more than one-fifth of the light moths escaped being killed
C. three times as many dark moths were kept safe as light ones
D. more dark moths were killed in industrial areas
4. Kettle Well’s work gives us a good example of     .
A. Air Pollution  B. Choice of Color   C. Laws of Nature  D. Changing Insects
5. As the air became cleaner,     .
A. the number of the light moths increased
B. the total number of the light moths remained unchanged
C. more of the darker moths would be recaught
D. the darker moths changed into the light ones before long D