By the time I have eaten my breakfast,it's eight o'clock.请解释

来源：学生作业帮编辑：作业帮分类：英语作业时间：2024/05/12 05:09:15

By the time I have eaten my breakfast,it's eight o'clock.请解释一下这一句中by the time的用法.
为什么从句要用现在完成时?
我一般见得都是By the time 过去时，过去完成时。没有见过By the time加现在完成时的，所以不太懂啊。

y the time 有两个意思
1、到...为止,一般要求主句用过去完成时.
He had left by the time we reached home.
当我们到家的时候他已经走了.
The movie had begun by the time we got there.
当我们到那儿的时候,电影已经开始了.
2、…当……的时候;
如果只是说过去某个时候的状况,用过去时,而不用完成时.
By the time the war was over ,death and suffering were to be seen everywhere.在战争结束的时候,到处可见死亡和饥饿.这里没有“死亡和饥饿”已经完成的意思,只是描述当时这个时间点的状况.所以用过去时.
By the time we arrived the meeting was over.
我们到达时,会议已结束了.

it's eight o'clock in the morning.it's time for the students --What's the time ---It's ____ eight o'clock .A.at B.on C.in -What's the time?-It's at eight o'clock.错在哪? （ It’s eight o’clock 1,Pick me up at eight o'clock,I__________ my breakfast by th It's eight o'clock.The students must have lessons now.(相同意思, What‘s the time?It's xxx .A) 3 o'clock B)It's eight C) seven it's eight o'clock the street is very b_______ It's eight o'clock什么the morning什么意思 It was eight o'clock when I ___ the station. 禁止自行车通行用英语怎么说?What's the time?It's at eight o'clock.中的at应该改为 I have my breakfast (at seven o'clock).对括号里的内容提问,是用What time