Câu trả lời:

1: Why don't we have a picnic this Sunday?

2: Traveling by train is not as tiring as traveling by train

3: Ho Chi Minh is the most exciting city in Vietnam

4: Because I didn't go to school yesterday, I visited my grandparents

5: Because it's raining, they don't want to go out

6: They are going to visit Ha Long Bay this summer vacation

7: He is going to learn Japanese next year

8: If you ask your teacher, he will help you with difficult exercises

9: If you study hard, you will do the end-term tests well

`1.` Why don't we have a picnic this Sunday?

`-` Cấu trúc: Let's + V...

`=` Why don't you + V...?

`2.` Travelling by train is not as tiring as travelling by car

`-` Cấu trúc SS (không) ngang bằng: S + be + (not) + as + adj + as + N/ pronoun

`3.` Ho Chi Minh city is the most exciting city in Vietnam

`-` Cấu trúc SSN tính từ dài: S + be + the most + adj

`4.` Because I visited my grandparents, I didn't go to school yesterday 

`5.` Because It's raining, they don't want to go out

`-` Cấu trúc `4+5` : Because + S + V, S + V..: bởi vì

`6.` They are going to visit Ha Long Bay this summer vacation

`-` They là số nhiều `->` are

`7.` He is going to learn Japanese next year

`-` He là số ít `->` ít

`-` Cấu trúc `6 + 7` : have a plan + to V = intend + to V = be going to + V

`-` Cấu trúc thì TLG: S + am/ is/ are + going to + V..

`8.` If you ask your teacher, he will help you with difficult exercise 

`9.` If you study hard, you will do the end-term tests well 

`-` Câu điều kiện loại 1 dùng để diễn tả điều kiện có thể xảy ra ở hiện tại hoặc tương lai

`-` Cấu trúc câu điều kiện loại 1 `(7+8)`: If + S + V(s/es), S + will/ can/ shall.. + V..