The job can be done with simple cutting tools or by hiring a professional shearer.

VOA: special.2010.09.07

Through the simple tools of classical conditioning then, the shoe becomes a conditioned stimulus giving rise to the conditioned response of sexual pleasure.

接下来，通过经典条件作用，鞋子变成了条件刺激,引起了性快感这一条件反应。

耶鲁公开课 - 心理学导论课程节选

"The unique thing about some of these decision tools is really how simple they are."

VOA: standard.2010.07.28