The answer is B: <span>electricity is required to produce the hydrogen fuel. This could still be polluting because much electricity is produced using fossil fuels. However, this question is a bit misleading. If electricity used to manufacture hydrogen is sourced from renewable energy, such as hydropower, solar or wind energy, then hydrogen power in turn is also not polluting.</span>
I believe the answer is 20 feet. According to McBurney and Collings, the average threshold of human hearing is the tick of a watch from 20 feet in very quiet condition.
The human hearing range is a description of the pitches and loudness levels a person can hear before feeling discomfort. There is a variety of sounds in our environment, ranging from faint sounds like birdsong and rustling leaves to louder sounds like music, yelling, and industrial noise.
Answer:
Weathering
Explanation:
You can use websites if it helps to
Answer:
energy changes from one form to another
Answer:
prokaryotes
Explanation:
prokaryotes where the earliest life forms ,simple creatures that fed on carbon compounds that were accumulating an Earth's early.slowly other organisms evolve that use the sun's energy along with compounds such as sulfides to generate their own energy.