问题:[选择题]
A.c<=48||c>=57&&c<=65||c>=90&&c<=97||c>=122
B.!(c<=48||c>=57&&c<=65||c>=90&&c<=97||c>=122)
C.c>=48&&c>=57||c<=65&&c>=90||c<=97&&c<=122
D.!(c>=48&&c>=57||c<=65&&c>=90||c<=97&&c<=122)
● 参考解析