—Whatdoesyourmotherdotokeepslim,Tom?  —Sheusually

問題詳情：

 —What does your mother do to keep slim, Tom? 

 —She usually ______ after supper.

A. walk              B. walks             C. is walking          D. to walk

【回答】

B

知識點：動詞時態

題型：選擇題