---How is it from here Ningbo to Xi'an?
---It's about two flight.
A. long, hour's
B. far, hour's
C. long, hours'
D. far, hours'
网友回答
A. long, hour's
B. far, hour's
C. long, hours'
(答案→)D. far, hours'
解析：结合下文答语可知上文问的是距离，故用how far进行提问。在复数名词的所有格后如果单词结尾已有s，则只需加’即可。故选D。