Question

—Excuse me, Mum. When can we have dinner?
—Not until it   in half an hour.

A．is prepared	B．has been prepared
C．will be prepared	D．was prepared

Answer 1

A

试题分析：句意：打扰了，妈妈。我们什么时候能吃饭？——知道半个小时后准备好了才行。当主句描述将来动作时，条件从句中一般用一般现在时态表示将来动作。从句主语是动作对象，故用被动语态，选A。