题目

Can you come and have a look at this problem_________ your earliest convenience? (用适当的词填空) 答案：【答案】at【解析】考查固定短语。句意：您可以在您方便时尽早来看看这个问题吗？固定短语at sb’s earliest convenience：在某人方便时尽早。故填at。已知等腰△ABC中，顶角∠A为36°，BD平分∠ABC交AC于D，那么AD：AC=    ．