单项选择题
A.is also called a static member B.is always a variable C.is never a method D.belongs to a single instance， not to the class as a whole E.always represents an operation
Anobjectis（）A.what classes are instantiated from.B.an i...
单项选择题An object is（）
A.what classes are instantiated from. B.an instance of a class. C.a blueprint for creating concrete realization of abstractions. D.a reference to an attribute. E.a variable.
Amethodis（）A.an implementation of an abstraction.B.an a...
单项选择题A method is（）
A.an implementation of an abstraction. B.an attribute defining the property of a particular abstraction. C.a category of objects. D.an operation defining the behavior for a particular abstraction. E.a blueprint for making operations.
1. public class X { 2. public object m （） { 3. objec...
1. public class X { 2. public object m （） { 3. object o = new float （3.14F）； 4. object [] oa = new object [1]； 5. oa[0]= o； 6. o = null； 7. oa[0] = null； 10. return o； 9. } 10. } When is the float object created in line 3， eligible for garbage collection？（）
A. Just after line 5. B. Just after line 6. C. Just after line 7. D. Just after line 8（that is， as the method returns）.
