问题补充：
I can read these new words, so I have to in the 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： 前半句 “我不会读这些新单词” 所以我要查字典。前半句是“words”是复数排除AB， 又因为代词应放在look 与up中间 所以选C
