1.组合的排列顺序有哪几种？怎样选用？
["\u6839\u636e\u7ec4\u5408\u6392\u5217\u56fe\uff1a\u7ec4\u5408\u7684\u6392\u5217\u987a\u5e8f\u6709\u4e24\u79cd\uff0c\u4e00\u79cd\u79f0\u4e3a\u201cS\u201d\u5f62\u6392\u5217\u6cd5\uff0c\u53e6\u4e00\u79cd\u79f0\u4e3a\u5206\u6bb5\u6392\u5217\u6cd5\uff0c\u8fd9 \u4e24\u79cd\u65b9\u6cd5\u90fd\u662f\u81ea\u7ad9\u5916\u5411\u7ad9\u5185\u81ea\u4e0a\u800c\u4e0b\u5730\u6392\u5217\u7ec4\u5408\u3002\u5bf9\u4e8e\u54bd\u5589\u8f83\u77ed\u7684\u8f66\u7ad9\u9009\u7528\u201cS\u201d\u5f62\u6392\u5217\u6cd5\uff0c\u5bf9\u4e8e\u54bd\u5589\u8f83\u957f\u7684 \u8f66\u7ad9\u9009\u7528\u5206\u6bb5\u6392\u5217\u6cd5\u3002"]