问题补充:
Technology has quickened the rate we communicate with the world around us.
A. for which
B. at which
C. to which
D. with which
答案:
A. for which
(答案→)B. at which
C. to which
D. with which
解析:句意:技术加快了速度,我们以这种速度与我们周围的世人进行交流。这里是定语从句,先行词是rate,以rate连用的是介词at,which在从句中作介词的宾语,故选B。