用括号内所给的正确形式填空。 1. This is one of _________(busy) underground stations in London. 2. —And now, better _________(go) to hospital. —All right. 3. Plenty of shops _________(be) open on Sunday mornings. 4. It’s only about an hour’s _________( f ly) from Qingdao to Beijing by air. 5. Ther e will be a school _________(leaver) party next week.