下列程序标注代码(A,B,C,D)中,正确的有 abstract class Takecare{ protected void speckHello(){ } //A public abstract static void cry( ); //B static int f( ){return 0;} //C abstract float g(); //D } A. protected void speckHello(){}; B. public abstract static void cry(){}; C. static int f(){return 0;} D. abstract float g();