题目

—Did Jim win?—There was no need to ask. His big smile s________ his success. 答案：【答案】showed【解析】句意：——吉姆赢了吗？——没有必要问。他灿烂的笑容表明了他的成功。句中缺少谓语动词，根据“There was no need to ask.”可知要用一般过去时；由“His big smile”及首字母s可推出是笑容表明他成功了，用show表示“表明”，其过去式是showed。故填showed。双曲线的渐近线方程是