用所给词的适当形式填空。
⑴They are going ________（celebrate）their party.
⑵The girl _______（feel）very happy.
⑶What time _______ the party _________（begin）?
⑷______（be）everyone in the class?
⑸Welcome to _________ （we）home.
⑹How many ________（puppy）are there over there?
⑺The assistants in the shop are ________（friend）to us.
⑻The _______ （one）lesson is about rules.
⑼_______（not forget）us.
⑽He is a friend of________ (we).