By the time he was twelve, Edison ______...

By the time he was twelve, Edison _______ to make a living by himself.

A．would begin

B．has begun

C．had begun

D．began

C 【解析】试题分析：考查时态。By…到…为止；与完成时连用。后面接the time he was twelve是过去时，故主句中使用过去完成时。句意：到他12岁的时候，Edison已经开始靠自己谋生了。故C正确。考点：考查时态

考点分析：

相关试题推荐

Charlie Chaplin______ a great actor from a child, and at last his dream ______.

A．dreamed to be ; came to true	B．dreamed of being; came true
C．dreamed about being ; was come true	D．dreamed of being; realized

查看答案

______ time went on , the weather got worse and worse.

A．While

B．When

C．As

D．With

查看答案

The _________ from the top of the tower was very wonderful.

A．sight

B．view

C．scene

D．scenery

查看答案

_______ him this time is difficult.

A．To refuse

B．Refusing

C．Refuse

D．Refused

查看答案

It is ten years since he _______ in this college.

A．works

B．worked

C．has worked

D．had worked

查看答案

试题属性