题目

22．Lawrence Craven, a doctor from the USA，is the author of several published reports, one of______ introduced the idea in 1953 ______aspirin could reduce the risk of heart attacks．        A．them; when          B．which; that     C．what; that       D．which; when 答案：B 解析: 考查从句。第一个空考查定语从句，which 用于介词后指代前文的reports。第二个空是由that引导同位语从句。具体说明idea的详细内容。小石子投入湖面将激起水波，使浮在水面的树叶在1min内起伏60次，与此同时，该波从中心向外扩延30m，则水波的波长为0.50.5m，波速为0.50.5m/s．