用作定语
▲～+n. This piece of news came from an authoritative source.这条消息来自权威人士。
David speaks in authoritative tones.大卫以命令的口吻说话。
用作表语
▲S+be+～
His words are the most authoritative among the specialists.这几个专家当中他的话最有权威。
Don't be so authoritative when you ask me to do something.你求我做事情时别用这种命令的口吻说话。
Authoritative orders came to the ambassador from the president.大使收到了总统下达的正式命令。
