I am afraid I Will not have got the correct answer by then 这里by then 能换成 at that time
问题描述：
I am afraid I Will not have got the correct answer by then 这里by then 能换成 at that time
答
不可,
by then （到那个时候） 相等于 by that time
不等于 at that time （在那个时候）
句子的意思是
到那个时候恐怕我还不会有正确的答案.