The horizontal distance between two successive crests is called the

a. wave height
b. fetch
c. wavelength
d. wave period

c. wavelength

Explanation:

The wavelength is a measure of the distance between two crest. It is taken as such because it gives the horizontal separation between adjacent points on consecutive wave peaks. It is also the same as the difference between two successive troughs. A crest on a wave is the peak of the oscillation. The trough is the adjacent depression.

b. 20: 5

explanation:

20% of the worlds population lives in southwest asia, and less than 5% of the world's

land area.

the rub-al-khali is also known as the arabian desert and the "empty quarter"