VOA慢速英语:US Is Hopeful for Nuclear Deal with Iran

final – adj. at the end; last

central – adj. in the middle of something : located in the center of a thing or place

collapse – v. to fall down or inward suddenly; to break down or fail suddenly in strength, health or power

trauma – n. a very difficult or unpleasant experience that causes someone to have mental or emotional problems usually for a long time