题目

My dictionary is lost. Could you help me________it?A.look for B.look up C.look through D.look after 答案：【答案】A【解析】句意：我的字典丢了。你能帮我找一下吗？考查动词短语，A. look for寻找；B. look up查找；C. look through浏览；D. look after照顾。根据前面“My dictionary is lost我的字典丢了”那么应该是帮忙找，故选A。6cm长的一条弦所对的圆周角为90°，则此圆的直径为    cm．