26. A 

- There are some fish below me and above me

27. B

- litter = how rubbish; Oh, no, they're littering!

28. C

- A plastic bag is around my leg. It's hard to swim [...]

29. D

- living things: vật sống; Please don't litter! It's bad for all living things

30. C

- I'm swimming in the lake

`B`. Writing

31. No one in our class is more intelligent than Nam (so sánh hơn tính từ dài: S1 + tobe + more adj + than + S2)

32. My brother would like to be an architect when he grows up (would like + to V(inf) = want + to V(inf): muốn)

33. It is very interesting to have a summer camp abroad (It + tobe + adj + to V(inf)

34. My father will go to Ho Chi Minh City by plane next Sunday (fly = go by plane)