${23.}$ A dictionary has just been bought by me.
→ bị động HTHT: S + have/has (not) + been + V3/ed + (by+O) + time
${24.}$The test can be done easily by students.
→ bị động dạng động từ khiếm khuyết: S + can/must/may/should/might ... (not) + be + V3/ed + (by+O) + time
${25.}$ That course hasn't been taught by Mr. Jonh since 1985.
→ bị động HTHT
${26.}$ It is believed that the thieves got in through the kitchen window.
The thieves are believed to have got in through the kitchen window.
→ bị động với "believe":
- It + is/was + believed + that + S2 + V2 + O2
- S2 + Vbe + believed + to_V/ to have V3/ed + O2
* Sử dụng to_V khi V2 ở thì HTĐ hoặc thì TLĐ
* Sử dụng to have V3/ed khi V2 ở thì QKĐ hoặc thì HTHT
${27.}$ She is said to work 16 hours a day.
People say that she works 16 hours a day.