Who runs as fast as Tom ______?
问题描述：
Who runs as fast as Tom ______?
A.does B.run C.do D.did
答
A
语言点：
1.时态要一致---排除D
2.数要和主语Tom 一致,三单形式----排除B,C
3.does 在这里是代动词,意为runs,用does 主要是为了避免重复