2. It must be innocuity, and has no stimulation, no side-effect and noninteracting with medicine. 医药中表面活性剂必须无毒、无刺激、无副作用且不影响药性。
3. The so-called happiness, is to be hope that things get, the resulting psychological state of a fresh temporary period of continuous stimulation process. 所谓快乐，就是得到期望所得到的事物后，所产生的一种心理状态，新鲜刺激持续的一段暂时性过程。
英英解释
n.
1. the act of arousing an organism to action
2. any stimulating information or event; acts to arouse action
3. (physiology) the effect of a stimulus (on nerves or organs etc.)
4. mutual sexual fondling prior to sexual intercourse
