To train a rat, the experimenter placed it in an operant conditioning chamber: a small plastic box with a lever at one end.
为了训练小鼠,实验人员把它放在一个操作性条件反射室:一个一端置有操作杆的塑料箱。
2
When a charged particle zips through the chamber, the vapour condenses into a trail of droplets showing the particle's path and, if the box is placed in a magnetic field, its electrical charge.