Chuyển sang câu bị động

Chuyển sang câu bị động:
1.everyone grows vegetables in the filed
2.he is playing batminton
3.Ba can play piano well
4.My mother gave a new dictionary
5.Nam built this house in 1990
6.they held this festival every yaer to welcome tourists
7.My father buys a new mobile in the morning
8.She sent a post card yesterday