do”结构作目的状语时,可以放在句首也可放在句中;“so as to do”结构只能放在句中。 Her mother plans to fly to Beijing at least four times a year (so as/in order)to visit her.她母亲计划每年至少四次飞到北京来看她。 2.不定式作结果状语 不定式作结果状语常用在下列句式中:so...as to;such...as to;...enough to;only to(常表示意外的或事与愿违的结果);too...to等。 I'm not so stupid(a fool) as to write it down. 我不至于愚蠢到会把它写下来。 Jane hurried back only to find that her mother had left. 简匆忙赶回来却发现她的母亲已经离开了。(表示“意外或事与愿违的结果”)