A.Y B.N C.0 D.1
A.(a>=0‖b>=0)&&(a<0‖b<0) B.(a>=0&b>=0)&&(a<0&b<0) C.(a+b>0)&&(a+b<=0) D.a*b>0
A.a'<=ch<='z' B.(ch>=a)&&(ch<=z) C.('a'>=ch)||('z'<=ch) D.(ch>='a')&&(ch<='z')
A.a<>0 B.!a C.a=0 D.a!=0
A.不定值 B.4 C.3 D.1
A.a/2==0 B.a%2==0 C.a%2!=0 D.a/2==1