Exposure to radiation and toxins. This is because the radiation can basically fry the sperm causing many reproductive issues in men.
i'm unsure of your statement, but i believe that the statement is false. A rake would add more physical activity, since you're using both leg muscles while walking, and arm muscles.
Answer:
https://www.pinterest.com/pin/451134087671358046
Explanation:
It's the labelled diagram
I would say Recycling or using alternate power sources such as solar or wind