It depends——看情况而定
One day a doctor went to a store and bought a pair of shoes. Before he left the shoes counter, he asked the salesgirl: " How long will this pair of shoes last?" 一天，一位医生到鞋店买了双鞋。他在离开柜台之前，问售货员：“这双鞋能穿多长时间？”
"It depends. If you don t use it, the shoes will never wear out."“看情况而定。如果您不穿它，那它们永远也不会坏。”
Several days later the salesgirl fell ill and went to a hospital. And the happened to be the customer she served. After the girl got the prescription from the doctor, she asked: "How soon will I get better with the medicine?"几天后，这位售货员病了，去医院看病。这位医生碰巧是那位顾客。 当售货员拿了处方后，问道：“吃了这药，我的病多长时间才能好呀？”
"It depends. " The doctor answered, "If you don t use it, you will never get better. “看情况而定。”医生说，“如果你不吃药，你的病永远也好不了。”