A.
Public class Dog{ String color = "黑色"; String type ="德国牧羊犬"; public void toString(){ return "这是一只"+color+"的"+type; } }
B.
Public class Dog{ String color = "黑色"; String type ="德国牧羊犬"; public String toString(){ return "这是一只"+color+"的"+type; } }
C.
Public class Dog{ String color = "黑色"; String type ="德国牧羊犬"; public toString(){ return "这是一只"+color+"的"+type; } }
D.
Public class Dog{ String color = "黑色"; String type ="德国牧羊犬"; public String toString(){ "这是一只"+color+"的"+type; } }