Chuyển chủ động sang bị động

ĐỀ BÀI: chuyển chủ động sang bị động
1. he isn't preparing the lesson now.
 the lesson...
2. they haven't seen her friend since Tet.
Her friend...
3. we won't help him tomorrow.
He...
4. the flowers should be watered every day.
They...
5. Tom didn't do his homework last night.
His homework...
6. where did you buy these pens?
 Where were...
7. the house has been built for 2 months.
They...
8. I usually play soccer on Sundays.
soccer...
9. her class is being cleaned now.
she...
10. he is going to cook lunch for me.
lunch...