push the envelope是“推信封”？？？

这6个短语很日常，起源却出人意料 1. Pass the buck 推卸责任 You were the one who took on this job. Don't try to pass the buck. 是你接手这项工作的，别想推卸责任。 2. Turn over a new leaf 洗心革面 They decided to give him a last opportunity to turn over a new leaf. 他们决定给他最后一次机会，让他重新做人。 3. Push the envelope 挑战极限 She continues to find new projects and push the envelope. 她继续寻找新的项目并突破极限。 4. Ring the changes 换汤不换药 We have been in this flat for years, but we ring the changes by moving the furniture around. 我们在这间公寓已住了多年，但我们不时将家具搬来搬去，变换摆法。 5. Leave someone in the lurch 不顾他人的安危 I am not the kind of person to leave a friend in the lurch.I will lend him the money. 我不是见死不救的那种人。我会借钱给他的 lurch: n. 突然倾斜；蹒跚；挫折 vi. 倾斜；蹒跚 vt. 击败 6. Lick into shape 塑造，整顿 A year in the army will lick him into shape. 在部队呆上一年就会把他锻炼成好样的。 lick: v. 舔；卷过；鞭打; 轻轻拍打