The rain looked as though it had ______ for the night.

The rain looked as though it had ______ for the night.
A、set off
B、set out
C、set in
D、set down
【正确答案】：C
【题目解析】：set off出发，引起，动身；set out出发，开始，陈述；  set in 开始，到来，流行； set down放下句意：雨看起来好像已经下了一夜了。