The de beers company, one of the longestminuslived monopolies, is facing increasing competition. one source of competition comes from people who might resell their previously owned diamonds. why is de beers worried that people might resell their previously owned diamonds?

Because previously owned diamonds would be a close substitute to newly mined diamonds and therefore reduce De Beers' market power.

the president has the power to appoint federal judges, ambassadors, and other "principal officers” of the united states, subject to senate confirmation of such appointments.

this is a pretty broad question and can be a pretty lengthy answer. since 1900, women have gained a lot more rights and have become active in the workforce. with women being in the workforce, men play a larger role in family life. many family tasks are shared between men and women, whereas, women used to be the sole family caretakers.

that should get you started at least.