`#Tran`

`1.` February has fewer days than January.

`->` S + be + short adj + er + than + ...

`->`  S + be + more + long adj + than + ...

$\Longrightarrow$ few là tính từ đặc biệt 

`2.` Hoa used to help her mother a lot of works after school.

`->` Cấu trúc đã từng: S + used to + `V^1` + ... 

`3.` The distance between my house to the stadium is about `3` kilometters

`->` The distance + between + place `1` + to + place `2` + be + about + ... : noi về khoảng cách

`4.` He will work at his office at `10` o'clock tomorrow.

`->` Cấu trúc thì TLĐ: S + will + `V^1`

`->` Dấu hiệu nhận biết: tomorrow

`5.` Solar energy will be used  to solve problem when energy shorrtage. 

`->` Cấu bị động: S + be + `V^(3,ed)` + O (by O)

1. February has  fewer days than january.

2. Hoa used to help mother a lot after school.

3. The distance between my house and the stadium is about 3 km.

4. He starts working in his office at 10 o'clock tomorrow.

5.Solar energy will be used to solve the problem of energy shortage.

Giải thích:

1. ngôi thứ 2 nên ta dùng has

Cấu trúc:

S + have/has + .....

có "than" nên ta thêm "er" ở từ few.

cấu trúc:

 S + be + short adj + er + than + ...

2. used đi với"to"

Cấu trúc:

S + used + to + Vinf( động từ nguyên mẫu)

3.  be: am/is/are

Cấu trúc:

The distance + between + place 1 + to + place 2 + be + about + khoảng cách:

4. Nó có từ " tomorrow"

=> thì tương lai đơn

Cấu trúc:

S + will + Vinf( động từ nguyên mẫu)

5. Cấu trúc:

S + be+ V3/ed + ...