What happens to humans when their oxygen drops from 20% to 5%?

Microorganisms are involved in each of the following processes excepta. smog production.b. food production.c. infection.d. o2 production.e. decomposition of organic material.

Many organizations release indexes used to measure the development of the world's countries. as we learned in this lesson, these indexes measure many factors, from life expectancy to happiness. in your opinion, what are the three most important factors we can use to determine how developed a country might be? explain your answers in a few sentences.

Earthquakes a.created the rock in arches utah b.can be caused by volcanic eruptions c.are caused by tsunami waves d.wear mountains down into hills