For Germany, what were the advantages and disadvantages of submarine warfare?

An advantage was your enemies would have no idea of you being there until you shot a torpedo, which would damage supplies and the ship. A disadvantage was that the subs were very crampled and dark and smelled because of how cramped it was

Explanation:

i think the answer is c, rivers.

explanation:

sometimes, borders fall along natural boundaries like rivers or mountain ranges. for example, the boundary between france and spain follows the crest of the pyrenees mountains. for part of its length, the boundary between the united states and mexico follows a river called the rio grande. the borders of four countries divide africa’s lake chad: niger, chad, cameroon, and nigeria.