Here are the completed zero conditional sentences:
1-If I **arrive** late at school, my teacher **gets** angry.
2-If you **mix** yellow and blue, you **get** green.
3-Plants **die** if you **do not water** them.
4-If the sun **shines**, you **do not need** an umbrella.
5-If you **stroke** the cat, it **purrs**.
6-If you **put** butter in the sun, it **melts**.
7-When it **rains**, it **pours**.
8-If you **go** to bed late, you **do not get** enough sleep.
9-If you **eat** too much candy, you **get** sick.
10-You **get** ice if you **freeze** water.