专业八级改错练习 第49期

【练习】

DDT, the most powerful pesticide the world had ever known,exposed nature’s vulnerability. Unlike most pesticides, which effect- __1

 tiveness is limited to destroy one or two types of insects, DDT is __2

capable of killing hundreds of different kinds at once. Developed in　1939, it first distinguished itself during the World War II, cleaning __3

South Pacific islands of malaria-caused insects for U.S. troops, while __4

in Europe being used as an effective de-lousing power. Its inventor　was awarded by the Nobel Prize. __5

When DDT became available for civilian use in 1945, there were　only a few people who expressed the second thought about this __6

new miracle compound. One was nature writer Edwin Way Teale,who warned, “A spray as discriminate as DDT can upset the economy __7

of nature of all insects are good, but if they are killed, things __8

 go out of kilter right away.” Another was Rachel Carson, who　wrote to the Reader’s Digest to propose an article about series of __9

tests on DDT being conducted not far from which she lived in Maryland. __10