英语名词+名词的问题

题目

英语名词+名词的问题
there was a dramatic increase in mobile calls from 2 billion to 46 billion minutes.The rise was particularly noticeable between 1999 and 2002,during which time the use of mobile phone tripled.我想请问一下time 和the use of中间不应该加个 of 手机使用的时间.

答案

这样解释也许你就会清楚了.
结构应该是：The use of mobile phone tripled during which/the time.
可见：use和time在这里没有任何直接关系.
亲：高老师祝你学习进步,每天都开心V_V!
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