1 1. 2 #define A(a) a 3 A(); 4 5 2. 6 #define B(a, b) (a,b) 7 B(a, ); 8 B(, b); 9 B( , ); 10 B(a,); 11 B(,b); 12 B(,); 13 14 3. 15 #define C(a, b, c) (a,b,c) 16 C(a, b, ); 17 C(a, , c); 18 C(, , c); 19 C(a, , ); 20 C(, b, ); 21 C(, , c); 22 C(, , ) 23 C(a,b,); 24 C(a,,c); 25 C(,,c); 26 C(a,,); 27 C(,b,); 28 C(,,c); 29 C(,,) 30