By the time we got to the cinema , the film _______ for half an hour.
A. Has begun
B. Had begun
C. Has been on
D. Had been on
Most environmental problems exist because adequate measure for preventing them taken in the past.
A. Was not
B. Were not
C. Were not being
D. Had not been
第一道,电影开始不是用begin吗???been on还真没遇到过
第二道,环境问题不是在过去之前没有做好,应该选D,过去的过去,为什么错了?
Most environmental problems exist because adequate measure for preventing them ______taken in the past.
第二道的空忘记搞上去了。。。