给定下面的代码,哪个选项中的代码是正确的覆盖? class BaseClass { p rivate float x = 1.0f ; protected float getVar ( ) ( return x;) } class Subclass extends BaseClass { private float x = 2.0f; ________________ // 覆盖父类 getVar 方法的声明 } } class Circle extends Ellipse { public Circle(double a) { ______________ } }