Question

5．如果他们不招待我们，我们就捉弄他们一下．
If they do not give us a treat，we'll play a trick on them．．

Answer 1

分析 If they do not give us a treat，we'll play a trick on them．

解答 答案：If they do not give us a treat，we'll play a trick on them．
这里用if引导的条件状语从句，遵循主将从现的规则，主句用一般将来时will+动词原形，主语we，play a trick on sb捉弄某人，故we'll play a trick on them．从句用一般现在时，主语they，招待某人give sb s treat，借助于do构成否定，故答案是If they do not give us a treat，we'll play a trick on them．

点评 if条件句的时态搭配
　　1．if从句用一般现在时，主句用一般将来时
　　If he runs he'll get there in time．如果他用跑的，他就会及时赶到那儿．
　　The cat will scratch you if you pull her tail．如果你拉猫的尾巴，它就会抓你．
　　2．if从句用一般现在时，主句用may/might/can
　　If the fog gets thicker the plane may/might be diverted．如果雾在大一些，飞机可能就会改在别的机场降落．
　　If it stops snowing we can go out．如果雪停了，我们就可以出去．
　　3．if从句用一般现在时，主句用must/should
　　If you want to lose weight you must/should eat less bread．如果你想减肥，你必须少吃面包．