help, bị động ạ When did people build that museum? _________

`->` When was that museum built ?

`-` Bị động - quá khứ đơn

`(+)` S + was/were + PII (by.......)

`(-)` S + was/were + not + PII (by........)

`(?)` Was/Were + S + PII (by........) ?

`#``K``a``c``h``i``n`