When you don’t know a word, you can in the dictionary.
A. look it up
B. set it up
C. give it up
D. pick it up
网友回答
(答案→)A. look it up
B. set it up
C. give it up
D. pick it up
解析：考查短语辨析。look up查询；set up竖立;建造；give up放弃；pick up拾起，收拾 ；学到;获得。句意：当你不认识一个单词的时候，你可以查字典。故A正确。