The correct answer is A. Acid rain forms from human activities and lowers the pH of rainwater below 7
Explanation:
The term "acid rain" is used to refer to rainwater with a low pH or a high acidity, this includes rainwater with a pH below 7 (solutions with a pH under 7 are acidic). In terms of formation, acid rain is mainly the result of human activities such as factories or cars that release pollutants into the atmosphere including nitric and sulfuric acids and these alter the natural pH of rain and makes it more acidic. Additionally, acid rain has negative consequences such as the death of fishes and other organisms in lakes, rivers, etc. because the acidity is toxic to many organisms. Thus, acid rain is the result of human activities and it lowers the pH of rain (Option A).
The correct option is (D) Gamma (

)
Explanation:Now this question is a tricky one because all of these options are somehow involved in radioactive decay; however, in this case the SYMBOL is required NOT the elements. There are three symbols involved in radioactive decay, which are:
1. α for alpha decay
2. β for beta decay
3. γ for gamma decay
In the options only one symbol is present which is
gamma. Hence option (D) Gamma ( 
) is the correct answer.
-i
The role of friction is of great importance when creating safety ramps and escalators because with the help of friction things move.
<h3>Why is it important to move objects slowly on ramps and escalator?</h3>
It is important to move objects slowly on ramps and escalator because the ramps and escalator moves object in the opposite direction of gravity. If we did not move objects slowly, then the objects or a person get damaged.
So we can conclude that the role of friction is of great importance when creating safety ramps and escalators because with the help of friction things move.
Learn more about friction here: brainly.com/question/24338873#SPJ1