NO.PZ2022090802000006
问题如下：
Which of the following is the closest example of a one-sided network?
(备注：原版书课后题原题。和真题的出题形式不同（真题只有三个选项）。大家做题时不用纠结题目形式，关注知识点原理即可)
选项：
A.An online employment website
B.A dating website for men and women
C.A social network for model train collectors
D.A website for home improvement contractors
解释：
SolutionC is correct. A social network for model train collectors involves a single group of users and thus is closest to a one-side network. The others involve two user groups: employers and job-seekers in A, men and women in B, and homeowners and contractors in D.
为什么是单边呢？买家和卖家都有
