随着年龄增长，皮肤中的胶原蛋白会逐渐减少。
As we age, the amount of ___collagen in our skin naturally decreases.
她每天服用胶原蛋白补充剂来保持皮肤弹性。
She takes ___collagen supplements daily to maintain skin elasticity.
As we age, the amount of ___collagen in our skin decreases.