1. By the time we arrived at the cinema, the film had finished.
=> Dùng cấu trúc "By the time trong thì quá khứ: By the time + S1 + V1(ed/PP), S2 + had + V(ed/PP)".

2. Plans for an extension to the ISS have been drawn by American scientists.
=> Đổi câu chủ động thành bị động.

3. When did you start working on the project?

4. Susan said that her parents had left for London at 5 p.m the day before.

=> Chuyển câu trực tiếp sang gián tiếp: Lùi thì QKĐ -> QKHT; đổi "yesterday" -> "the day before".

                                                                                                                      -pa-

1. By the time we arrived at the cinema, the film had finished.

2. Plans for an extension to the ISS have been drawn by American scientists.

3. When did you start working on the project?

4. Susan said that her parents had left for London at 5 p.m the day before.