________ if you want to do something, or you won’t be able to do it well.

Please       forget your homework. You are supposed to hand it in tomorrow moming.

 "_____ your meeting is!" he offered them his sincere congratulations.

You can see a large signal on the wall：＿＿＿＿! 

 ________it is to throw snowballs at each other on the playground after snow!