题目

—I couldn't find David anywhere. —Well, he      have gone far-his coat's still here. A. shouldn't         B. mustn't            C. can't              D. wouldn't 答案：C用边长为30厘米的正方形地砖铺一段长18米、宽3米的人行道路面，至少需要多少块这样的地砖？