If you don’t know how to spell new words in a dictionary.A. look them upB. look up them

问题补充：

If you don’t know how to spell new words, in a dictionary.

A. look them up

B. look up them

C. look them after

D. look them for

答案：

(答案→)A. look them up

B. look up them

C. look them after

D. look them for

解析：句意：如果不知道怎么拼这些新单词，可以查字典。Look up查阅（字典）；当宾补是代词时要放在动词和副词中间，故选A；look after照顾；look for寻找。