回複：我母親的綠卡過期/失效了，超過一年沒回來了，如果想再回美國，是否又去申請旅遊簽證回美（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