If you drive along the river bank it is twenty miles out of your way.
If you take your mobile phone into class, it must be turned off.
We don't use calculators when we write tests.
If you push this button, the volume increases.
If you close the door, it locks automatically.
I wear my old boots when I work.
When I cook salads, I use only olive oil.
When I concentrate, please don't make so much noise.
Unless prices rise, it  isn't a good investment.
Unless someone asks you politely, refuse to do anything.

The zero conditional is used for when the time being referred to is now or always and the situation is real and possible. The zero conditional is often used to refer to general truths. The tense in both parts of the sentence is the simple present. In zero conditional sentences, the word "if" can usually be replaced by the word "when" without changing the meaning.
Zero conditional используется когда время, в котором происходит действие  - это "сейчас" или "всегда" и ситуация реальная и возможная. Также это тип условных предложений используется , когда речь идет об общепринятых истинах. Время в обеих частях предложения будет Present Simple. В этих предложениях слово "if" обычно может быть заменено на "when" без изменения значения предложения.