Chương 34. Bài Tập (Exercises) (tr.506)
Đáp ánTrang 506
IV.
- think - is knocking
- don't know - hasn't spoken
- circles
- are you staring - haven't seen
- have you seen
- play
- is increasing
- haven't been waiting
- goes - is traveling
- are - have been
- haven't watered
- has lost
- haven't finished - have been dealing
- does your father do - is - aren't working
- Have you ever seen - have seen
