初二英语（用所给词的适当形式填空）

初二英语（用所给词的适当形式填空）
1.While the boy ______(walk) down the street,a UFO _____(land).
2.The girl was shopping when she saw the alien _____(get) out.
3.I had a very ______（unusually)experience on Sunday.
4.The ststion _____(crowd)and Linda couldn't see her dog _____(somewhere).
5.While Hai Yan was at the _____(doctor),I was going to class.