The CheckboxMenuItem class extends the MenuItem class to support a menu item that may be checked or unchecked.

42. What is a task's priority and how is it used in scheduling?
A task's priority is an integer value that identifies the relative order in which it should be executed with respect to other tasks. The scheduler attempts to schedule higher priority tasks before lower priority tasks.

43. What class is the top of the AWT event hierarchy?
The java.awt.AWTEvent class is the highest-level class in the AWT event-class hierarchy.

44. When a thread is created and started, what is its initial state?
A thread is in the ready state after it has been created and started.

45. Can an anonymous class be declared as implementing an interface and extending a class?
An anonymous class may implement an interface or extend a superclass, but may not be declared to do both.

46. What is the immediate superclass of Menu?
MenuItem.

47. What is the purpose of finalization?
The purpose of finalization is to give an unreachable object the opportunity to perform any cleanup processing before the object is garbage collected.

48. Which class is the immediate superclass of the MenuComponent class?
Object.

49. What invokes a thread's run() method?
After a thread is started, via its start() method or that of the Thread class, the JVM invokes the thread's run() method when the thread is initially executed.

50. What is the difference between the Boolean & operator and the && operator?
If an expression involving the Boolean &  operator is evaluated, both operands are evaluated. Then the &  operator is applied to the operand. When an expression involving the &&  operator is evaluated, the first operand is evaluated.
If the first operand returns a value of true then the second operand is evaluated. The &&  operator is then applied to the first and second operands. If the first operand evaluates to false, the evaluation of the second operand is skipped.