【问】 请就下面两道试题分析一下so as to与so...as to的区别：
 1. As I approached the gates I switched off the headlamps of the car____prevent thebeam from swinging in through the window and waking Jack.
 A. so as to B. in order
 C. so that D. for(Nelson，450A)
 2. “If John doesn’t come to work on time，he may be fired.”
 “Surely he isn’t so foolish____not to realize that. ”
 A. so B. and
 C. but D. as(TOEFL，74.11)
 【答】 so as to总是连在一起，后面紧跟动词不定式，它在意义上相当于in order to(后者更正式一些)。它所引导的动词不定式总是起目的状语的作用，因此，把so as省略掉之后，动词不定式的意义常常保持不变。例如：
 1. Students should take notes (so as) to make revision easier. (CGEL)
 学生应当记笔记，以便容易复习。
 2. We started early so as to get there before ten.(《高中英语课本》，P.141)
 我们很早就动身了，以便10点前到达那里。
 3. Turn the volume down so as not to wake the baby. (CGEL)
 把音量调小一些，免得把婴儿吵醒。
 4. The test questions are kept secret，so as to prevent cheating. (LDCE)
 试题应保密，以免作弊。
 5. Then Columbus took the egg and struck its small end gently upon the table so as to breakthe shell a little.(许国璋《英语》第二册)
 哥伦布拿起鸡蛋，把它的小头轻轻往桌子上一敲，把蛋壳打碎了一点。
 so...as to结构中，so总是与as to分开用，在so之后可加入形容词，as to所引导的动词
 不定式总是起结果状语的作用。这一结构在语义上相当于so+形容词+that从句。例如：
 1. so odd an idea as to be unbelievable(CGEL)
 一个如此古怪以致不能令人相信的想法
 2. Who could be so mean as to do a thing like that? (DAI)
 是谁这样卑鄙竟然做出这样的事情来?
 3. Are you so naive as to imagine this is not taking place elsewhere? (Mis)
 你那么天真竟然认为这不是在其他地方发生的?
 4. Some really keen enthusiasts go so far as to build their own record players and radiotransmitters. (New Concept English，Book 3，L.46)
 某些确实热衷于此道的人甚至自己安装电唱机或发报机。