Fill in the blanks in each of the following statements: a) The ______class is used to create a menu object. b) The ______method of class JMenu places a separator bar in a menu. c) JSlider events are...

a) The ______class is used to create a menu object.

b) The ______method of class JMenu places a separator bar in a menu.

c) JSlider events are handled by the ______method of interface______ .

d) The GridBagConstraints instance variable______ is set to CENTER by default.