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。