VOA慢速英语:US, Allies Weigh Iran Nuclear Deal

Verification - n. to prove, show, find out, or state that (something) is true or correct

Sanctions - n. an action that is taken or an order that is given to force a country to obey international laws by limiting or stopping trade with that country, by not allowing economic aid for that country, etc.

Refinery - n. a place where something is refined, purified