DESIGN: Randomized and double blind observation.

设计：随机双盲法观察。

Methods: Randomized double blind study was employed.

方法：随机双盲对照临床研究。

Methods The random and double blind method was used.

方法采用随机双盲方法。

DESIGN: Randomly double blind and control experiment.

设计：随机双盲对照实验。

Methods:this was a randomized, double blind controlled trial.

方法：采用随机双盲对照研究。