If you want better grades,you ______ watch so much TV.答案是shouldn't ,可以用couldn't吗shouldn't ,couldn't ,有什么区别呢

If you want to do better 同义句 If you want to ） if you want you You'd better give up smoking if you want to keep nealthy这段话翻译成中文怎么说? If you want to learn something,you had better pay_______in class. If you want to sell your product well ,you,d better ___(做广告)it if you want to do better in your study ,you must be ___(impatient). If you want to let me listen to you ,Had better be take out your skills If you want to learn a c______,you'd better learn its culture You'd better shape up if you want to stay on.什么意思 if you want to catch the train you'd better go (立即) if you don't want to be late ,you'd better ()a ()打的 If you don't want to be late,you’的better（）a（）. If you want to be in time ,you'd better get going对吗 If you want better grades,you ___ watch so much TV.为什么填 shouldn't If you want to get good grades,you'd better write the article _____(不同） If you want to learn English better,you should pIf you want to learn English better,you should p_____ it everyday. if you want ro have a better future,come here and learn是否有语病 So when you want your parents to let you do something, you will have better success if you really s