He'll be a teacher by the time____ hr thirty
A is
B had been
C will be
D is goingto be
选择一个正确的~并说明原因

He'll be a teacher by the time__A__ hr thirty
A is
B had been
C will be
D is goingto be
到什么时间
http://zhidao.baidu.com/question/3645175.html?si=4
从句用过去时，主句用过去完成时
came, had started
或
从句用一般现在时，主句用一般将来时或将来完成时
By the time the Olympic Games start, we will have finished/ finish the construction.
by the time 有两个意思: （注：此回答仅仅是一个方面）

一:by the time可以翻译为:这时候,在此时.相当于at the/that time.

By the time he had lost contact with the Party.
这时他已和党失去联系。

By the time we had settled in the third bus.
这时我们已在第3辆大汽车里坐好。

二:by the time,意为:在....之前已经....

by the time our teacher came in ,we had started speaking English.
在老师进来前,我们都已经开始讲英语了.

你这句话的结构是对的.只是翻译过来感觉有点不是很顺口.

by the time when got to the bus station,the bus had left.
在我们到达车站时,汽车早就开走了.


by+时间名词。意为：“到…时（已发生某事），此时谓语多用完成时；最晚、不迟于…，在…之前”。如：by now/then/this time/next Friday/the end of/three o`clock等。

By the end of last year,another new gymnasium had been completed.(2003上海·春）到去年年底，又有一座新体育馆峻工了。


参考文献：http://blog.sina.com.cn/calendula28