Many provinces have been hit with smog. If _______ unsolved, the problem may lea

题干

Many provinces have been hit with smog. If _______ unsolved, the problem may lead to more serious results.

A．having left

B．to leave

C．left

D．leaving

上一题下一题 0.64难度单项选择更新时间:2014-03-07 04:07:53

小学学科试题库

初中学科试题库

高中学科试题库