关于虚拟语气的
虚拟语气中关于跟将来事实相反的,从句用should do或were to do,怎么区分用这两种形式呢?比如：
If they were to arrive before we leave,we should have a wonderful dinner.
If they should arrive before we leave,we should have a wonderful dinner.
这两种说法好像都说的通啊,那种不对呢?