问题详情：
Thanks for your invitation, but I’m so sorry I can’t go. I need to my younger sister at home.
A. look at B. look up
C. look after D. look for
【回答】
C。考查短语辨析。由语境知: 我需要在家照顾我妹妹。look at“看”; look up“查找(资料等)”; look after“照料; 照顾”; look for“寻找”。
知识点：动词和动词短语
题型：选择题
