Đáp án : 

1. The mono-wheel is a single - wheel bike.

2.  There have been many interesting transport inventions nowadays.

3. How long does it take you from Ha Noi to Da Nang ?

4. Although they were tired, they wanted to watch the film.

giải thích : 

1. sắp xếp câu

2. sắp xếp câu

3. mẫu câu với how long  : 

How long + does it + take you + from + địa điểm 1 + to + địa điểm 2 ? 

4. mẫu câu với although : 

1.   Although + S1 + V1, S2 + V2

2.   S1 + V1 + although, S2 + V2 

1. The mono-wheel is a single-wheel bike.

2. There have been many interesting transport inventions nowadays.

3. How long does it take you from Ha Noi to Da Nang?

-> How long + do/does + it + take + SO + from ... to ...: mất bao lâu từ ... đến ...

4. Although they were tired, they wanted to watch the film.

-> Although + clause, clause: hai MĐ trái ngược nhau