1. The weather was hot so he carried the bed on to the roof of his house.

    Since it was hot, he carried the bed on to the roof of his house.

2. Unless you smoke, you will suffer from lung cancer.

3. All the students love the principal because of his kindness.

    He is loved by all the students because he is very kind.

1) He carried the bed on to the roof of his house because of the hot weather
->> The weather was so hot that he carried the bed on to the roof of his house
->> Since the weather was hot, he carried the bed on to the roof of his house
2) Don't smoke or you will suffer from lung cancer
->> Unless you smoke, you will suffer from lung cancer
3) All the students love the principal because he is very kind
->> All the students love the princial since he is very kind
->> He is a kind princal so all the students love him

Chúc bạn học tốt!^-^