Objectives: to examinate stability of melatonin and its improving sleep function and its safety as a healthy food.

目的：检验保健品中褪黑素含量的稳定性及其改善睡眠功能和毒理学安全性。

Methods The case-control association study and were adopted to examinate color perception before and after intraocular lens implantation and in 97 patients.

方法用病例对照研究方法，选择行白内障手术的患者97例，进行色觉检查及填写统一设计的问卷调查。

We should self-examinate and revaluate Dong Zhongshu's history status by the way of "put oneself in another's position ". We should affirm his indelible historic contributions.

我们应当以一种＂同情之了解＂的立场和态度来反思和重估董氏之历史地位，肯定其不可磨灭的历史贡献。

At the start of a match and whenever he changes his racket during a match a player shall show his opponent and the umpire the racket he is about to use and shall allow them to examinate it.

比赛开始时及比赛过程中运动员需要更换球拍时，必须向对方和裁判员展示他将要使用的球拍，并允许他们检查。