4 biện pháp:

+ trồng cây để làm tiếng ồn phân tán

+ làm tường chắn tiếng ồn 

+ Sử dụng những món đồ nội thất cách âm.

+ Đề ra nguyên tắc 

9 engagement

10 done

11 marked

12 expected

13 fed

14 looked after

15 driven

25. He/ not/ smoke/ cigarette/ for/ a month. (Build the sentence using the cues given).

He hasn't smoked cigarette for a month

29. This painting is more expensive than my painting.( not as ….as)      

my paiting is not as expensive as this painting

41. water/ drink/ everyday? (Use the suggested words to make question with How much)

 How much water do you drink everyday?

72. What do you think about making pottery? (Answer the question using the grammar structure of “ THINK”)

I think making pottery interesting because I can make many pretty things.

73. She needs twelve eggs to make two cakes. ( Make a sentence with the underlined part)

79. It is useful to collect the used glass bottles for making a vase.

I find collect the used glass bottles is useful for making a vase

6 ở trên mạng à bạn ;))

ta có:

  a + b - c = 21

=> a/2 = b/3 = c/4 = a + b - c/ 2 + 3 - 4 = 21/1 = 21

<=> a = 21.2 = 42

<=> b = 21.3 = 63

<=> c = 21.4 = 84.

tham khảo