1. How far is it from Ho Chi Minh city from Hue ?
-> How far + is it + from + nơi chốn + to + nơi chốn ?
2. Solar energy will be used to protect the environment.
-> Câu bị động tương lai đơn: S + will + be + Vpp
3. Although it rained hard, I went to class on time yesterday.
-> Although + S + V = In spite of + N/Ving : mặc dù
4. Although they have very little money, they are happy.
-> In spite of having very little money, they are happy.