5.Nga said that she had to finish her homework then

*Đây là câu gián tiếp nha, cách làm thì bạn coi trong sách giáo khoa để rõ hơn nha

6.Sydney Opera House was completed in 1973

*Đây là câu bị động: S+V+O=S+be+ Vpp+ (by+O)

7.The reports haven't been finished by her yet

*Giải thích như câu 6

8.The poem was written by Clemen Clarke Moore in 1823

*Giải thích như ở câu 6

9.My friend told me that she/he could repair the bicycle herself/ himself

*Giải thích như ở câu 5

10. Lan's mother told her that she had to go to bed early

*Giải thích như câu 5

=>

5. Nga said that she had to finish her homework then.

-> câu tường thuật (lùi thì, must -> had to/now -> then)

6. Sydney Opera House was completed in 1973.

-> bị động QKĐ was/were V3/ed

7. The reports haven't been finished (by her) yet.

-> bị động HTHT have/has (not) been V3/ed

8. The poem was written by Clemen Clarke Moore in 1823.

-> bị động QKĐ

9. My friend told me that he could repair the bicycle himself.

-> câu tường thuật (can -> could)

10. Lan's mother told her that she had to go to bed early.

-> câu tường thuật (must -> had to)