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__

　　答案：

　　1.which—whose。whose在這里作關系限定詞，與effectiveness構成名次詞組在關系分句里作主語。whose的主語可以是人，也可以是物。

　　2.destroy—destroying。be limited to 詞組里的to并不是不定式標記to，而是介詞to，要謹訪介詞to“冒充”不定式to。其他類似的詞組還有be opposed to, object to, get used to等等。考試大

　　3.cleaning—clearing。clean和clear這對形近而且意近的動詞容易被混淆，但是clean指“使某地方沒有灰塵，使干凈”，而clear強調“清理不需要的東西，而且clear 可與of連用，而clean很少。（這兩個詞的改錯之前也有遇到過，大家都要記住啦！）

　　4.caused—causing。此句中malaria－causing insects 相當于insects that caused malaria，因此是主動關系，所以應選擇-ing形式。

　　5.by－/。the Nobel Prize實際上是award的另一個賓語，還原成主動結構是…awarded the inventor the Nobel Prize.所以這里應刪掉by。

　　6.the－/。短語second thought或second thoughts意為“仔細斟酌，三思”，如：Robert didn’t give a second thought to borrowing $2,000 from him.

　　7.discriminate－indiscriminate。discriminate有“區別”之意，indiscriminate意為“不加以選擇，不分青紅皂白”。從上下文來看DDT的特點是沒有分辨性：它既能殺死有害的昆蟲又能殺死有益的昆蟲。

　　8.but－and/so。本句的兩個意群的關系是順接，不是轉折，因此應選用順接的連詞，如and和so等。

　　9.^series－a。series這個名詞屬于單數復數同形，它經常與a和of構成詞組a series of表示“一系列的”。

　　10.which－where。from這個介詞后面應接一個介詞表具體方位，因此這里只能用表方位的副詞where。