If you heat water, it (boil/boils).
Answer: boils (zero conditional)
If they (not be) so busy, they would come to the party.
weren’t (Second Conditional)
If you (not eat) breakfast, you get hungry by noon.
don’t eat (Zero Conditional)
If she (call) me later, I will let you know.
calls (First Conditional)
If we had left the house earlier, we (not miss) the flight.
wouldn’t have missed (Third Conditional)
If people (not eat) food, they die.
don't eat (zero conditional)
If she had studied more, she (pass) the exam.
would have passed (Third Conditional)
If the weather is good, we (go) to the beach.
will go (First Conditional)
If I (have) a car, I would drive to work.
had (Second Conditional)
If we (not spend) all the money, we would have gone on vacation.
hadn’t spent (Third Conditional)
If ice (melt), it turns into water.
melts (Zero Conditional)
If I (win) the lottery, I would buy a yacht.
won (Second Conditional)