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一. 选择题（155） 1.下面中哪两个可以在 A 的子类中使用：（ ） class A { protected int method1 (int a, int b) { return 0; } } A. public int method 1 (int a, int b) { return 0; } B. private int method1 (int a, int b) { return 0; } C. private int method1 (int a, long b) { return 0; } D. public short method1 (int a, int b) { return 0; } 2.What will be the output when you compile and execute the following program. class Base{ void test() { System.out.println(Base.test()); } } public class Child extends Base { void test() { System.out.println(Child.test(); } public static void main(String[] a){  Child anObj = new Child(); Base baseObj = (Base)anObj; baseObj.test(); } } Select most appropriate answer.( ) A.Child.test() Base.test() B.Base.test() Child.test() C.Base.test() D.Child.test() 3.What will be the output when you compile and execute the following program.  class Base{ static void test(){ System.out.println(Base.test()); } } public class Child extends Base { void test(){  System.out.println(Child.test());  Base.test(); //Call the parent method } public static void main(String[] a) { new Child().test(); } } Select most appropriate answer. ( ) A.Child.test() Base.test() B.Child.test() Child.test() C.Compilation error. Cannot override a static method by an instance method  D.Runtime error. Cannot override a static method by an instance method 4.What will be the output when you compile and execute the following program. The symbol ’ ?’ means space. 1:public class Base{ 2: 3: private void test() { 4: 5: String aStr = ? One? ; 6: String bStr = aStr; 7: aStr.toUpperCase(); 8: aStr.trim(); 9: System.out.println([ + aStr + , + bStr + ]); 7: } 8: 9: public static void main(String[] a) { 10: new Base().test(); 11: } 12: } Select most appropriate answer.( ) A.[ONE,? One? ] B.[? One? ,One] C.[ONE,One] D.