(1) in case
  例:He left early in case he should miss the last train.
  他动身得早,以免误了最后一班火车。
  (2) for fear (that)
  例:He handled the instrument with care for fear (that) it should be
  damaged.他小心翼翼地摆弄那仪器,以防把它弄坏。
  (3) so that
  例:Let’s take the front seats so that we can see more clearly.
  让我们坐到前面的座位上,以便能看得更清楚些。
  (4) in order that
  例:He got up very early so that/in order that he might/could catch the early bus.为了赶上早班车,他起了个大早