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。

youdao

Chris Hall, of the Rail Accident Investigation Board, said that Mr Lund would have had "no reason to believe" the train would change direction, which was most likely caused by the driver forgetting to lock the reverse lever.

BBC: North Yorkshire Moors Railway death: Family to sue