写出同义句，一空一词。
【小题1】His parents bought him some nice books yesterday.
His parents _____some nice books _____him yesterday.
【小题2】I'm afraid I can't go to your party this Sunday.
It's impossible for me _____ _____to your party this Sunday，I'm afraid.
【小题3】He wanted to study in Peking University.
He ___ _____to study in Peking University.
【小题4】The family welcomed their friends warmly.
The family gave _____ _____welcome to their friends.
【小题5】It happened at night，so nobody saw it.
It _____ _____at night，so nobody saw it.