By the time he was 10,he ____(make) a living by selling newspapers.

题目

By the time he was 10,he ____(make) a living by selling newspapers.
By the time he was 10,he ____(already make) a living by selling newspapers.答案是was already making
可by不都是用完成时的吗?应该是过去完成时才对啊?
By the time 能用进行时吗,

答案

答案是正确的
1.是讲他was十岁的时候,基本时态是过去式.
2.讲的是他十岁那一个阶段一直靠卖报纸赚钱,所以用进行式