多项选择题
A.At most one listener of each type can be registered with a component.
B.Mouse motion listeners can be registered on a List instance.
C.There exists a class named ContainerEvent in package java.awt.event.
D.There exists a class named MouseMotionEvent in package java.awt.event.
E.There exists a class named ActionAdapter in package java.awt.event.
单项选择题 What will be the appearance of an applet with the following init（） method？ public void init（） { add（new Button（"hello"））； }
多项选择题 Whichmodifiersandreturntypeswouldbevalidinthedeclarationofaworkingmain（）methodforaJavastandaloneapplication？（）
单项选择题 Whichstatementsconcerningtheswitchconstructaretrue？（）