he is one of the world-famous musicians,by the time he was six,he composinghe is one of the world-famous musicians,by the time he was six,he composingAhad begun B begins C would begin D have begun.为什么不选D而选C呢
问题描述：
he is one of the world-famous musicians,by the time he was six,he composing
he is one of the world-famous musicians,by the time he was six,he composing
Ahad begun B begins C would begin D have begun.为什么不选D而选C呢
答
he was six,是过去式,D.have begun 是现在完成式,时态不符合,故选C !