by 时间造句

1.By the time he was fourteen year sold，he had learned maths all by himself.到14岁的时候，他就已经自学了数学。

2.I shall have finished it by the time you come back. 你回来以前我就把它做完了。

3.By the end of the match, they had kicked two goals and we had kicked four.比赛结束时，他们踢进了2分我们踢了4分。

4.They must have finished their work by this time.他们现在一定已经完成工作了。