VOA慢速英语:How Freud Changed What People Thought About the Mind

if successful是if it is possible的省略形式。

2.Another is that we do not necessarily know what drives us to do the things we do.

drive to do驱使某人做某事

例句：I do not mean to drive her mad.
      我无意令她生气。

3.Patients usually have to pay for the treatment themselves. Health insurance plans rarely pay for this form of therapy.

hardly, rarely, scarcely与seldom的用法

hardly“刚刚，不完全”，表示程度：I hardly know him. “我几乎认不出他了”，表示还是能认出或者说“我刚刚能认出他”；

hardly与any连用表示“几乎没有”，与ever连用表示“几乎从来不”；

scarcely的意思与hardly更接近。rarely“不经常”，表示事物发生的频率：

He rarely goes there. 他很少(不经常)去那里。seldom“很少，不经常”，它与rarely更接近。