问题补充:
Please don stand up in class until you .
A. are told
B. will be told
C. are told to
D. will tell
答案:
A. are told
B. will be told
(答案→)C. are told to
D. will tell
解析:句意:只到你被叫到才能站起来。Not …until…直到…才…主句是将来时态,从句要用一般现在时态。故排除BD;此句,要用被动语态,故排除D;这里是tell sb to do的被动形式即sb be told to do;这里的to后省略了stand up;但是这里的to不能省略,故选C。