【TOEFL核心词汇】No.41 紧张

英语自学网

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只听写例句。前面的单词不用听写。
这一期有两个例句哦。Skyscrapers put a severe strain on a city's sanitation facilities.
Going still further, they succeeded in breeding new strains that were resistant to diseases, grew faster and larger, and flourished in water of different salinities and temperatures.