根据句意，用括号内所给单词的适当形式填空。
He is the __________(four) child of his family.
My father __________(teach) Chinese in a secondary school.
How many _________ (wait) are there in the big restaurant?
The schoolbags on the shelf belong to ________（they）.
The things in the shop are too expensive and there are few _________(shop) there.