一道选择题目

显示全部楼层 · 2011-2-6 16:56:38

64.I am sure Mary has been here and________ . .
A. did what required her B. has done what required her
C. has done what was, required of her D. did what has been required of her
标准答案是C，需要详细说明

千问 · 2011-2-6 16:56:38

选C，有and做连词的时候前后时态要一样，所以排除AD，require常与to ,of 连用意思是需要，一般不单独使用。还有疑问Q我，我在线！

千问 · 2011-2-6 16:56:38

B
requiredof 需要排除CD，时态强调做过了，用did