Luggage may not be brought into the building ________ a guard has checked it fi

题干

Luggage may not be brought into the building ________ a guard has checked it first.

A．when

B．because

C．after

D．unless

上一题下一题 0.64难度单项选择更新时间:2015-03-12 08:04:07

小学学科试题库

初中学科试题库

高中学科试题库