If you ___ water to 100°C, it ___. (heat, boil)
If you heat water to 100°C, it boils.
If people ___ enough sleep, they ___ tired. (not get, feel)
If people don’t get enough sleep, they feel tired.
If it ___ tomorrow, we ___ at home. (rain, stay)
If it rains tomorrow, we will stay at home.