Fast Growing Vegetables Why Does Acid Rain Make Vegetables Grow Faster?

Why does acid rain make vegetables grow faster? - fast growing vegetables

done in school, but only an experiment, we left a few seeds on a piece of gauze with water from acid rain and other seeds in water for several days. After those few days of soaking cotton seeds in water, more acid rain increases the water is clean!
What is the reason? I thought that acid rain has been ruined, do not make them grow.