彻底刷牙有助于口气清新。A thorough brushing helps to freshen up your mouth.空气稀薄清新，其间日光蒙眬，寒气逼人。The air was thin and crisp, filled with hazy sunshine and frost.她的房子光线充足，空气流通，清新整洁。Her house is light and airy, crisp and clean....
顺势疗法是基于“以毒攻毒”的原理。Homeopathic treatment is based on the "like cures like" principle.格里菲思教授解释了那种药物的工作原理。Professor Griffiths explained how the drug appears to work.这些人对科学原理一窍不通。These people lack all understanding of scienti...