I know I'm a bit late but just in case you still need some of the answers.
1: Oxygen
2: Change in shape
3: Water breaking down into hydrogen and oxygen
4: I think it's Milk but I might be wrong.
I might be wrong about some of them, sorry it's not much.
Answer:
If and then for example: If you get at least 6 hours of sleep, you will do better on tests than if you get less sleep.
Explanation:
Option A is correct answer
