what type of economic activity is predominant in the deserts of north Africa and south Asia?

Answer 1

https://www.cia.gov/library/publications/the-world-factbook/
Use this link to look up specific countries. For example, when I look up Sri Lanka (south Asia), I get this:
https://www.cia.gov/library/publications/the-world-factbook/geos/ce.html
Scroll down to the section on Economy.

Answer 2

Since those are https:// sites, you'll need to copy and paste them into your web browser.

Answer 3

how does the increase in use of ethanol in the United state impact other place in the world?