Acivilization may start to form when people have control over which physical feature?

a. desert

b. river

c. sea

d. plains

B. river

Explanation:

A river gives the inhabitants a reliable source of:  

The first great civilizations, all grew up in river valleys, as Egypt developed alongside the Nile river.

(b) britain had a much larger navy than the u.s.

(d) the u.s. had a small army compared to britain.