问题
单项选择题
The machines are made ()at full speed.
A．work
B．working
C．to work
D．to be worked
答案
参考答案：C
解析：
make...do的被动形式是...be made to do。故选C。
搜题请搜索小程序“爱下问搜题”
The machines are made ()at full speed.
A．work
B．working
C．to work
D．to be worked
参考答案：C
解析：
make...do的被动形式是...be made to do。故选C。