问题
选择题
. I have taught hundreds of students,___________ having been working in their fields for years.
A．some of whom
B．some of them
C．most of whom
D．who
答案
答案：A
考查定语从句。句中先行词为students，在从句中作some of的宾语，故用关系词whom。句意：我已经教过几百位学生，其中一些已经在他们领域工作多年了。