1、look down upon/on看不起某人，轻视某人反义词是look up to，两个一起记比较好记，单个词分开来看，look看，down下面，引申出看不起look down upon/on sb.
2、look up to尊敬想到lookdown upon/on，up上，看得起某人，也就是尊敬的look up tosb.
3、look up在（词典参考书）中查找、look up the dictionary
4、look into调查look into sth.look into doing sth.
5、look forward to期望，盼望这里的to 是介词，look forward to doing sth.
6、look through浏览look through sth.
