返老还童药

例句：

1. 1. The old man was given a pill to help him regain his youthful vigor.
   那位老人被给了一粒药丸，帮助他恢复年轻时的活力。
2. 2. The scientist developed a new drug that could reverse the aging process.
   这位科学家研发了一种新药，可以逆转衰老过程。
3. 3. She took the medicine every morning and felt her skin looking younger than ever before.
   她每天早上服用这种药，感觉皮肤比以前更年轻了。