When you meet some new words you can in your dictionary.A. look it upB. look up itC. loo

问题补充：

When you meet some new words, you can in your dictionary.

A. look it up

B. look up it

C. look them up

D. look up them

答案：

A. look it up

B. look up it

(答案→)C. look them up

D. look up them

解析：本题的含义是当你遇到一些新的单词，你可以在字典中查询它们，look up表示查询，后跟某物，若是名词在up前后都对，若是代词，只能放在up之前，本题为代词，代替前句的复数单词words，故用them。