If条件句专练I单项选择1. If hehard, he will get good grades.A. study B. studiesC. will study D. studied2. I want to know if Maryto the party tomorrow.A. go B. wentC. will go D. goes3. Everyone must dress up. If you, they wont let you in.A. dont B. wontC. cant D. mustnt4. Mary will go to Sanya if shea five-day trip.A. have B. hadC. will have