题目内容：

were it not for the adoption of the open policy ,things ___they are today.
A would never be B would never have been 为什么不能选a,请告诉我具体原因,

优质解答

虚拟语气,对过去的虚拟.
另外从句 were it 是if it were的省略.主句需用would/should+ have done
如果当初没有采取开放政策,事情（局面）不会是今天这样（已经发