题干

(2013·青岛一模)All flights ________ owing to the heavy fog, many passengers could do nothing but take trains.
A.to be cancelledB.were cancelled
C.have been cancelledD.having been cancelled
上一题 下一题 0.64难度 单项选择 更新时间:2014-03-28 01:12:16

答案(点此获取答案解析)