Question

【題目】If you see a flag ___ __ outside a window, you may know someone in that house __ ____ a birthday.

A. fly, have B. flew, has

C. flying, is having D. flying ,has

Answer 1

【答案】C

【解析】

試題分析：句意：如果你看到窗戶(hù)外面一面旗升起，你可能知道在房子里某個(gè)人正在過(guò)生日。短語(yǔ)see sb./sth. doing sth.表示看見(jiàn)某人/某物在做某事；主句中的賓語(yǔ)從句缺少謂語(yǔ)動(dòng)詞，這里用現(xiàn)在進(jìn)行時(shí)，其結(jié)構(gòu)是is/are doing的形式，根據(jù)題意。故選C。