Answer:
17. The mountains get white when it snows.
18. If you mix red and yellow, you get orange.
19. If he work a lot, he earns a lot of money.
20. If we watch TV, we enjoy a lot.
Step-by-step explanation:
Conditional sentences are known to be sentences that show known facts or hypothetical situations or events and their result.
Zero conditional are sentences that actually describe known truths and scientific facts which are possible and real.
From the given sentences, it's seen that each of the sentences speak of something real and possible. It is very possible and real that when it snows, the mountains get white.
A conditional sentence usually consists of two clauses:
1. the condition or if-clause
2. the main or result clause.