问题 the color of which的用法

There are 12 umbrellas in the doorway, the color of which is blue.老师这句话中的the 名词 of which用的对吗？是只要替换color就都可以用吗？有什么需要注意的吗？

问题 是否需要加the

The greater the population there is in a locality, the greater the need there is for water, transportation,and disposal of refuse. 请问老师这句话的原本语序是There is the greater the population in a locality, there is the greater  need for water, transportation, and disposal of refu...

话题 one … or another

话题 yes or no

话题 brothers or sisters

话题 not a…or…

话题 whether or not

话题 one or two

话题 he or she

话题 more or less

话题 his or her

话题 a…or twoy

话题 连词and or用法

问题 定语从句强调疑问

I caught sight of the criminal in the hotel where i stayed.强调宾语：It was the  criminal that I caught sight of in the hotel where i stayed.I bought the book I like.强调宾语：It was the book I like that I bought.这样是没错的吧？

问题 whether...or...是什么词（引导什么从句）

请问专家：whether...or...是什么词性？它用于引导什么从句？麻烦专家老师举例说明一下，谢谢！