这类题目用题干中的materials in countryside 来去找乡下的特征往往会正中洋人的圈套！！！
除了排除法之外，我们可以把这种题当成推理题去做：
即先明确为何 cities have a higher heat capacity? 'heat from the Sun can be conducted into these materials and stored' 热量进入到了materials中并储存了下来。
反过来想 为何 countryside has a lower heat capacity？因为热量进不去！再看选项。。。哪个最接近
