1. If there weren't gravity, the moon would shoot into space instead of traveling around the earth.
2. If I were your age, I would do differently.
3. If I should find your passport, I will elephone you at nine.
4. If I had wings, I would not have to take an airplane to fly home.
5. This letter will be in Ho Chi Minh in two days. I'm sure if I send it today, it will arrive on time.
6 I am not an astronaut. If I were an astronaut, I would take my camera with me.
7. Most people know that oil floats on the water. If you pour oil on the water, it will float.
8. It is been a long drought. It hasn't rained for over a month. If it doesn't rain soon, a lot of crops will die. If the crops die many people will go hungry this coming winter.
9. Would people be able to fly if they had feathers instead of hair?