He ---(live) in the city since he left his hometown.参考答案是has

has lived 和has been living 都可以.
since + 从句,与现在完成时连用,has lived是现在完成时,现在完成时表示过去发生的动作对现在造成了影响.has been living 是现在完成进行时,它表示某一动作从过去就开始,一直延续到现在,还有可能延续到将来.