He went into his room the light and began to work.A. has turned B. turned offC. turned on

问题补充：

He went into his room, the light and began to work.

A. has turned

B. turned off

C. turned on

D. Has turned off

答案：

A. has turned

B. turned off

(答案→)C. turned on

D. Has turned off

解析：turn转动，转变；turn off关掉；turn on打开。句意；他走进他的房间，打开灯，开始工作。联系上下文，可知本句描述的是过去的动作，故用一般过去时态。选C。