问题
选择题
Barack Obama delivered a speech to 500 local youths during his visit to China, many of were from Fudan University and Tongji University.
A．them
B．whom
C．which
D．those
答案
答案：B
题目分析：考查非限制性定语从句。先行词是500 local youth，指人用who/whom/that，排除C；根据逗号判断，是非限制性定语从句，有and的话，是并列分句，A、D不能引导定语从句，排除A、D；故选B。