1 when is his homework usually done by him ?

-> câu bị động kết hợp thì HTĐ dạng nghi vấn ta có cấu trúc 

( wh - question ) + be + S + VPII + by + O

2 what should be done now

-> câu bị động động từ khiếm khuyết should kếp hppw wh question

-> wh - question + should be + VPII + by +0

3 a new house is going to be bought by his parents

-> câu bị động thì TLG

-> s + be + going to be + VPII + by + O

4 has the teacher;s question answered by you ?

-> câu bị động thì HTHT 

-> have / has + S + VPII + by + O

5 what was being done by lan when you came

câu bị động thì QKTD 

-> s + was / were + being + VPII + by + O

6

what is being done by him at the moment

-> câu bị động thì HTTD

câu bị động thì HTTD 

-> s + be + being + VPII + by + O