单项选择题
Which statement is true about the class of an object that can reference the variable base？（）
A.It can be any class. B.No class has access to base. C.The class must belong to the geometry package. D.The class must be a subclass of the class Hypotenuse.
单项选择题 What is the result？（）
多项选择题 Which three are valid on line 12？（）
单项选择题 Giventhefollowingsixmethodnames：（1）addListener（2）addMouseListener（3）setMouseListener（4）deleteMouseListener（5）removeMouseListener（6）registerMouseListenerHowmanyofthesemethodnamesfollowJavaBeanListenernamingrules？（）
