The human body is thought to contain 40 trillion bacteria
The answer is B. Oxygen
To do aerobic respiration, oxygen is needed. Without oxygen, the body won't produce some substance which will be needed to do Krebs cycle and electron transport. Most of the energy will be produced by the electron transport so without oxygen the amount of energy produced will be much less.
<span>Although there are a little more than 100
different elements in the world, only a small number comprise a majority of the
different systems on Earth. The elements that make up rocks and minerals of
solid Earth include silicon, oxygen, iron, magnesium, and other trace amounts
of various elements. Living organisms are composed primarily of carbon, oxygen,
and hydrogen. Other elements in living matter include calcium, nitrogen,
phosphorus, potassium, and trace amounts of other elements. </span>
1 Eyesore: Unpleasant to see
2 Noise Pollution: They are noisy for people who live around them
3 Huge initial capital investment: Costs of starting up is huge. Cost of manufacturing is huge
4 Not always running: Can’t rotate when there is no wind