There are many ways humans can reduce the amount of endangered and extinct species. However, I would say by reducing pollution and logging/mining. Nearly 318 species have become extinct due to pollution. The reduction of carbon emissions would be a good way to curb the amount of pollution produced by humans.

velocity is a vector so it has a magnitude and direction so the answer would be B
An inactive(dead) version of the disease is given, so that the body can build antibodies but now suffer from the symptoms
Answer: 2. Precipitation
Explanation:
Aerobic cellular respiration requores oxygen. Photosynthesis does, as well.