A、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px">kk>='A'&&kk<='Z' </span>
B、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px; TEXT-DECORATION: none">!(kk>='A'||kk<='Z')</span>
C、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px">(kk+32)>='a'&&(kk+32)<='z'</span>
D、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px">isalpha(kk)&&(kk<91)</span>