He is one of the world-famous musicians. By the time he was six, he ______ composing.
A.had begun
B.begins
C.would begin
D.was beginning
答案:A
题目分析:考查谓语动词的时态 by +过去时间,谓语动词(主句)常用过去完成时态;by+将来时间,谓语动词(主句)常用将来完成时态
He is one of the world-famous musicians. By the time he was six, he ______ composing.
A.had begun
B.begins
C.would begin
D.was beginning
答案:A
题目分析:考查谓语动词的时态 by +过去时间,谓语动词(主句)常用过去完成时态;by+将来时间,谓语动词(主句)常用将来完成时态