Hair's natural shine is supplied by its own conditioner, sebum, an oil composed of waxes and fats and also containing a natural antiseptic that helps fight infection. Too much sebum results in greasy hair and conversely, too little sebum makes dry hair. 头发的自然光泽来自它自身的护发素：油脂，它含有蜡和脂肪，还含有抗感染的自然抗菌剂。油脂含量过多会导致油性发质，相反，油脂含量过少则会导致干性发质。
The man who is a pessimist before forty-eight knows too much; the man who is an optimist after forty-eight knows too little. 未逾四十八岁的悲观主义者，是知道得太多之人; 而年逾四十八岁的乐观主义者，是知道得太少之人。
Too much work and too little rest often lead to illness. 过量的工作和过少的休息会引起疾病。
