The number of the college students who(have )mobile phones has been greatly increasing since 2001
问题描述：
The number of the college students who(have )mobile phones has been greatly increasing since 2001
为什么用have不用单数呢?不是The number of 谁能讲清谁就讲,简单的翻译就别写上了,
答
这里就要弄清楚句子的成分与结构了,第一个have是做定语从句来修饰students的,是指拥有手机的学生,所以当然用的是复数了,第二个has才是你想的那样子修饰the number的呢,是指（学生）数一直在增长的意思么.