If you don’t know the word, why don’t you _______ in the diction

If you don’t know the word, why don’t you _______ in the dictionary?
A、look at it
B、look after it
C、look up it
D、look it up
【正确答案】：D
【题目解析】：look at it 看着它；look after it 照顾它；look up 看望，查找，当宾语为代词时，一般放中间，如 look it up句意：如果你不知道这个词，为什么不在字典里查呢？