Which is a description of the Paleozoic era? O A. The hottest era
O B. The era of humans
O C. The age of the dinosaurs
O D. The rise of life

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.

d) a constitutional amendment

the communist manifesto is an 1848 political pamphlet by the german near the end of the manifesto, the authors call for a "forcible overthrow of all existing social conditions",  ..