回复：我母亲的绿卡过期/失效了，超过一年没回来了，如果想再回美国，是否又去申请旅游签证回美（B2）

She needs to give up the green card first and then, apply for the B2 visa at the ame time or later. She probably can get the 10-year validity B2 visa with multiple entries.

See this website for information on abandonment of green card:

 

http://www.immihelp.com/greencard/abandonment-greencard.html