is working
was working
has worked
had worked
本题考查动词的时态。句中的when I visited her last year确定了过去的某一时间点,所以此处表示当时动作正在进行,所以用过去进行时。故答案为B。 句意:Susan已经辞去那份报酬丰厚的工作,去年我去看她的时候她正在社区当志愿者。