The ancient sumerians modified their environment to increase food production by

s the president shall be commander in chief of the army and navy of the united states, and of the militia of the several states, when called into the actual service of the united states; he may require the opinion, in writing, of the principal officer in each of the executive departments. sooo yeahhh

explanation:

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

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