VOA慢速英语:Trump Sends Letter to China's Xi

constructive - adj. helping to develop or improve something

benefit - v. to be useful or helpful to (someone or something)

commend - v. to praise (someone or something) in a serious and often public way

sensitive - adj. likely to cause people to become upset

provocation - n. an action or occurrence that causes someone to become angry or to begin to do something​