What is the definition of blacklist ?

What is the purpose of the system of checks and balances

How has u.s. participation in international economic development efforts affected other countries? o a. it has made some countries decide they no longer want close ties with the united states. b. it has ended diplomatic ties with countries that refuse to participate. c. it has raised money to poor nations grow their economies. d. it has caused the united states to intervene militarily to stop human rights abuses.

Plz how did the jews of the diaspora preserve their heritage?