(3) compilation error, type syntax error

(4) Compilation error, undefined identifier floating point

(4) compilation error, loss of AVG identifier; sign

(4) Compilation error, undefined identifier AVG

(5) SCANF is not defined.

(5) undefined identifier b

(5) The identifier c is not defined.

(7) Data may be lost when converting from floating-point type to plastic type.

(The identifier before PRINTF is missing;

(7) The function PRINTF is undefined.

(7) The identifier f is not defined.

(7) Possible input case in Chinese and English

7) Questions about the possible input of uppercase and lowercase Chinese and English.

(8) lost; Before}