【正文】 F. p2 = (ClassC)p4。 D. p2 = (ClassC)p1。 Which three are valid? (Choose three.) A. p0 = p1。 24. ClassA p3 = new ClassB()。 22. ClassB p1 = new ClassB()。 (f. a)。} 38. } Invoked with: Foo f = new Bar()。 37. public void addFive(){ += 5。 (f )。 at line 2 in B 062 31. class Foo{ 32. public int a = 3。 at line 2 in GrizzlyBearjava C. add import .*。 2. 3. public class Salmon extends Fish { 4. public void consume() { /* do stuff */ } 5. } If both classes are in the correct directories for their packages, and the Mammal class correctly defines the findSalmon() method, which change allows this code to pile? A. add import animals. mammals.*。 6. ()。 2. 3. public class MainClass{ 4. public static void main(String[] args){} 5. } And MainClass exists in the /apps//pany/application directory. Assume the CLASSPATH environment variable is set to . (current directory).Which two java mands entered at the mand line will run MainClass? (Choose two.) A. java MainClass if run from the /apps directory B. java if run from the /apps directory C. java classpath /apps if run from any directory D. javaclasspath . MainClass if run from the /apps//pany/application directory E. java classpath /apps//pany/application:. MainClass if run from the /apps directory F. java if run from the /apps//pany/application directory BC 061 Given two files, and : 1. package 。 D. Beta b = (Beta)(Alpha)x。 B. Foo f = (Delta)x。 32. } 33. } What is the result? A. Canada B. null Canada C. Canada null D. Canada Canada E. Compilation fails due to an error on line 26. F. Compilation fails due to an error on line 29. E 058 10. interface Foo{ } 11. class Alpha implements Foo{ } 12. class Beta extends Alpha{ } 13. class Delta extends Beta{ 14. public static void main(String[ ] args){ 15. Beta x = new Beta()。} 27. } 28. public class Euro extends Money{ 29. public String getC(){return ()。 23. public String getC(){return country。 13. Building build2 = (Building)barn1。 11. Object obj1 = (Object)build1。 9. Barn barn1 = new Barn()。 24. (() + , + () 25. + , + ())。 22. Car car = new RaceCar()。}} 13. class RaceCar extends Car{public int speed(){return 150。 5. } What can directly access and change the value of the variable name? A. any class B. only the Target class C. any class in the test package D. any class that extends Target C 055 11. abstract class Vehicle{public int speed(){return 0。 3. } 1. public class AImpl implements A{ 2. public void doSomething(String msg){} 3. } 1. public class B{ 2. public A doit(){ 3. //more code here 4. } 5. 6. public String execute(){ 7. //more code here 8. } 9. } 1. public class C extends B{ 2. public AImpl doit(){ 3. //more code here 4. } 5. 6. public Object execute(){ 7. //more code here 8. } 9. } Which statement is true about the classes and interfaces? A. Compilation will succeed for all classes and interfaces. B. Compilation of class C will fail because of an error in line 2. C. Compilation of class C will fail because of an error in line 6. D. Compilation of class AImpl will fail because of an error in line 2. C 052 053 Insert six modifiers into the code such that it meets all of these requirements: 1. It must be possible to create instances of Alpha and Beta from outside the packages in which they are defined. 2. When an object of type Alpha (or any potential subclass of Alpha) has been created, the instance variable alpha may never be changed. 3. The value of the instance variable alpha must always be A for objects of type Alpha. 054 1. package test。 public void draw(){/* code here */} } F. public abstract class Circle implements Shape{ private int radius。 public void draw()。 public void draw()。 } B. public abstract class Circle extends Shape{ private int radius。 7. = y。 4. public abstract void draw()。 10. } 11. } What is the result? A. 1 B. 12 C. 14 D. 123 E. Compilation fails. F. An exception is thrown at runtime. C 049 Place code framgmets into position so the output is: The quantity is 420 050 1. public abstract class Shape{ 2. private int x。 5. new Venus().go(x, y)。 What is the result? A. Compilation fails. B. Cannot add Toppings C. The code runs with no output. D. A NullPointerException is thrown in Line 14. A 047 048 1. public class Venus{ 2. public static void main(String[ ] args){ 3. int[ ] x = {1, 2, 3}。 51. (Mushrooms)。 33. } 34. 35. public void removeTopping(String topping){ 36. (Cannot remove pepperoni)。 15. } 16. 17. public void removeTopping(String topping){ 18. (topping)。} class Widget extends Gadget{} AC 046 10. public class Pizza{ 11. ArrayList toppings。} F. class Gadget{Spring s1。} E. class Gadget{} class Widget extends Gadget{Sprocket s1。} class Gadget extends Widget{} D. class Gadget{Spring s。} C. class Widget{Sprocket s1。} B. class Widget{} class Gadget extends Widget{Spring s1。 AE 045 Gadget hasa Sprocket and Gadget hasa Spring and Gadget isa Widget and Widget hasa Sprocket Which two code fragments represent these relationships? (Choose two) A. class Widget{Sprocket s。 super(name, baseSalary)。 = mission。 super()。 = mission。 B. = mission。 6. } 7. } 8. public class SalesPerson extends Employee{ 9. double mission。 3. public Employee(String name, double baseSalary){ 4. = name。} is added to the Plant class. D 044 1. class Employee{ 2. String name。} is added to the Plant class. D. The code will pile if public Plant(){this(fern)。} 5. } 6. public class Tree extends Plant{ 7. public void growFruit(){} 8. public void dropLeaves(