不定式的特殊句型so as to

1） 表示目的；它的否定式是so as¹ not to do。
　　 Tom kept quiet about the accident² so as not to lose³ his job.　
　　　　 汤姆对事故保持沉默是为了不丢掉他的工作。
　　 Go in quietly⁴ so as not to wake⁵ the baby.
　　　　 轻点进去，别惊醒了婴儿。

2)　so kind as to ---劳驾
　　 Would⁶ you be so kind as to tell me the time?
　　　　 劳驾，现在几点了。