I can still remember that it is since the 1990’s, _____ we began to use cell pho

题型：不详难度：来源：

I can still remember that it is since the 1990’s, _____ we began to use cell phones,_______ the number of mobile users has greatly increased．

A．while; when

B．when; what

C．before; that

D．when; that

答案

D

解析

考查强调句式第一空是when引导定语从句，表示“我们在那个时候开始使用手机”，第二空是强调句式的引导词，被强调的部分是时间状语，因此D项正确。