The correct answer is this one: "human industrialization." Air pollution comes from human industrialization. Because of too much industrialization, there are a lot of excess and wastes in any form: air or even liquid and solid wastes.
There are many reasons why Zachary can't concentrate. He might have something on his mind that is bothering him, he could be hungry, he could not have a lot of energy. The best thing Zachary could do to help the paper not suffer is leave his desk and paper alone for about a half an hour, and maybe eat something, or just take a break. Maybe take a nap to get some energy back up so that he can get everything he needs in his paper.
Answer:
2 g per kg
Explanation:
Most research indicates that eating more than 2 g per kg of body weight daily of protein for a long time can cause health problems.
