VOA慢速英语:US, Japan, S. Korea Denounce Latest North Korean Missile Test

exclusive – adj. available to only one person or group

provocative – adj. causing discussion or argument

ironclad –adj. very strong and secure, too strong to change

inflammatory – adj. causing anger

obligations – n. things that are required to be done by a rule or law

ballistic missile – n. a weapon able to travel great distances

defy – v. to refuse to obey

challenge – n. the act of questioning authority or some action

grave – adj. very serious

impeachment – n. the action of charging a public official with crimes while in office