Question

More and more people have come to realize that if we had taken effective measures much earlier,...

More and more people have come to realize that if we had taken effective measures much earlier, the air quality ______ so seriously now. A．is not polluted B．would not be polluted C．had not been polluted D．would not have been polluted

Answer 1

B

试题分析：句意， 越来越多的人意识到如果我们早点采取有效地措施，现在空气污染就不会这么严重了。If条件从句是对过去的虚拟，故用过去完成时，而主句是对现在的虚拟，故用would do形式。 点评：所谓错综时间条件句即条件从句与主句所指时间不一致，如从句指过去，而主句即指的是现在或将来，此时应根据具体的语境情况，主、从句动词的形式应根据各自所表示的时间进行调整。