In the past few years, sea ice in the Arctic as a result of global warming.
A. had melted
B. has been melting
C. melted
D. is melting
网友回答
A. had melted
(答案→)B. has been melting
C. melted
D. is melting
解析：考查时态。根据in the past few years可知是与完成时连用的，在根据句意是指海冰一直都在融化。所以使用现在完成进行时。句意：在过去几年里，因为全球变暖，海冰一直在融化。