【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