1. If you do not change the default close operation, what happens when the user clicks on the close button on a JFrame object? 2. Why is it sometimes necessary to place a component inside a panel and...

1. If you do not change the default close operation, what happens when the user clicks on the close button on a JFrame object?

2. Why is it sometimes necessary to place a component inside a panel and then place the panel inside a container governed by a BorderLayout manager?

3. In what type of situation would you present a group of items to the user with radio buttons? With check boxes?