“show a leg”不是“秀出一条美腿”，真正含义是起床；露面。

【例句】
Come on, show a leg! We have to get on the road soon.
拜托，快点起床！我们得尽快上路。

Show a leg! It's time you were all up and about-breakfast is in five minutes' time.
醒醒！你们都该起来了，五分钟后用早餐。