6. Our exercises haven't been done by us.
7. Have they been seen in the room by you?
8. Has the garbage been collected by Ba?
9. Where have the flowers been planted by Giang?
10. Why have books been read by you so often?
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Câu bị động thì HTHT:
S have/has(not) been VPII by O.
Have/Has S been VPII by O?
Wh- have/has S been VPII by O?