have you seen Anna?Yes ,she----------books in library Ai.is looking for B.looked for

问题描述:

have you seen Anna?Yes ,she----------books in library Ai.is looking for B.looked for

A.不过我觉得没有选项的话was looking for更合理,因为提问者使用了现在完成时
be doing是现在进行时
did是一般过去时
相比较a更贴合语句意思.