lookat和lookup什么时候用

look up 向上看， 查找（在词典中查单词）,

look up 查询

If you don't know a word, you can look it up in a dictionary.

如果你有不识的字,可以查字典。

look at 看... (注视某人或某物)

Look at the map, please.

请看这张地图。