Question

if和unless的用法

1.If you _____(be)happy,we ____(be)happy.2.Jack___(miss)the early bus if he ____(not get) up early3.Plastic ___(melt)if it ___(get)too hot.4.If you go across the bridge.you ___(find)the museum.5.单项选择____ you go to the supermarket at 7 p.m.,you can buy lots of cheap food.A.If      B.Unless   C.Whether    D.When  求解并且解释,我只有初中水品,不要说太深奥.还有When 和If的用法有什么区别吗?? 

Answer 1

1.If you _are____(be)happy,we _are___(be)happy.2.Jack_missed__(miss)the early bus if he _couldn't__ get_(not get) up early3.Plastic __will melt_(melt)if it __gets_(get)too hot.4.If you go across the bridge.you will find___(find)the museum.5.单项选择_A___ you go to the supermarket at 7 p.m.,you can buy lots of cheap food.A.If B.Unless C.Whether D.When

怎么解释呢，字面意义就已经可以区分很清楚了。