1. I am not a astronaut. If I [???] (be) an astronaut, I (take) the photos of Turkey from space.
2. If you [???] (put) a stone in the water, it (go) down.
3. If there (be) no water on earth, we (not, exist).
4. If you [???] (be) a bird, where you (fly) to?
5. Anna (pass) the test if she (study) hard enough.
6. Sea water is salty. If the oceans (have) fresh water, we (have) a lot of drinking water.
7.If a Y-chromosome (combine) with an X-chromosome during fertilization, a male baby (become).
8. I (not, do) that if I (be) you.
9. If he (get) any worse I (take) him to the doctor's.
10.If the snow (get) any worse we[???] (have to) stop walking.