网址:http://m.1010jiajiao.com/timu3_id_798131[举报]
A.-2a和-2b B.a+1和b+1 C.a+1和b-1 D.2a和2b
A.-2a和-2b
B.a+1和b+1
C.a+1和b-1
D.2a和2b