高三复习科技文阅读训练（一）皮肤老化是怎样造成的呢？皮肤老化的原因很多，其中有些与个人体质有关，有些则因外界因素影响造成。不均衡的饮食习惯会导致过度肥胖或体重不足，更可能造成这两种情况交替产生。此外机体各种组合成分，如碳水化合物、油脂、蛋白质、维生素... The third year review of science and technology reading training (a) how to cause skin aging? There are many causes of skin aging, some of which are related to the individual’s constitution, and some of which are caused by external factors. Unbalanced eating habits can lead to excessive obesity or underweight, and it is more likely that these two situations will occur alternately. In addition, various combinations of body components, such as carbohydrates, oils, proteins, vitamins...