If the waste that society creates is properly managed, it can be stored or expelled in ways that aren't as toxic to the environment.
A placebo is kind of a "fake" treatment but, typically the person receiving a placebo is unaware it has no medical effect on them so they believe they are feeling better. For example, a lot of anxiety meds are placebos and people don't know so their brain tricks them into thinking they are feeling less anxious. This could be used in experiments where a group believes they are affected to see how they react
Provided that there's no diagram, most molecules have particular areas on the molecules, called the "active area" that act as a lock to a particular substrate's molecular structure, providing the key.
An enzyme's active area is only able to be "unlocked" by a certain substrate's "key".
The answer is letter A. In most organisms cellular respiration usually involves oxygen to produce the most energy. Except in the process of fermentation, where the cells are deprived with oxygen causing it to form bacteria and other forms of organisms within the fermented sample.