1. If we reuse thrown away rubbish, the environment will be more clean
2. If she doesn't work hard for the exam, she won't pass the exam.
3. You will gain weight if you eat too much fast food.
4. Unless he tells me the truth, I can't help him.
5. If we save water and energy, we will save the human life.
6. We will save our world if we protect the environment
7. She will take a taxi if she want to go to the hospital.
8. Unless he passes the exam, he will be very tired.
9. I will buy a new dress if I have enough money
10. If we use the car all the time, it will run out energy.