B.
31.comfortable
32.swimming
33.well
34.different
35.unhealthy(a trong bài phải chuyển thành an nữa nhé)
36.illness
37.collection
38.explanation
C.
39.A->are growing
40.A->saying(after+V-ing)
41.B->rang
42.B->himself
43.C->do
44.B->were performed
45.B->helping
46.C->came and gave
D
47.The sister asked Tom if he was hungry.
48.The little has put a lot of effort in the work.
49.When did you study medicine?
50.John wasn't strong enough to go to school.
51.Peter is taller than Tom.
E.
52.pollution
53.ill
54.laws
55.smoke
56.lung
57.Lead
58.health
59.it
60.climate
61.floods