选择正确的语句填在下列程序的横线处，使程序正常运行。 package ch1; import java. io. *; import j ava. util. *; class C45 implements Seritizable ______Public Thread t = new Thread(new T45(), "t"); public intcnt = 0; public C45() { t. start ( ) class T45 implements Runnable public int[] a = new int[4]; public void run() { for(int i - 0; i ＜ 4; i++) { a[i] - i +4; } } } public class ex45 { static String fileName = "ch1//file45.txt"; public static void main(String[] args) throws Exception { C45 bj = new C45 (); FileOutputStream fos = new FileOutputStream(fileName); ObjectOutputStream os = new ObjectOutputStream(fos); oos. writeObject (obj); oos.clese (); fos.close (); System. out, println (obj . toString ( ) ); } }

A．transient

B．protected

C．package

D．final

[单选题]下列程序的运行结果是______。 package ch1; import java.io. *; public class ex28 { public static void main (String args [] ) throws IOException { try { File f1 = new File("ch1//dir28"); f1.mkdir(); File f2 = new File(f1, "file59.txt"); FileOutputStream fos =

[单选题]下列程序执行后的结果是______。 package ch1; import java.io.*; public class ex22 { static, String filename = "ch1/kfile22.txt"; public static void main(String[] args) { try { FileWriter fr = new FileWriter(filename); PrintWriter pr = new PrintWriter(fr); String

[单选题]在下列程序的横线处填入正确的语句，实现RandomAccessFile类使用。 package ch1; import java. io. *; public class ex27 { public static void main(String args[] ) { try { RandomAccessFile in = new in.close ( ); } catch (Exception e) { e.printStackTrace (); } } }A．RandomAccessFile

[试题]在下面程序的横线处填上适当的语句,使该程序的输出为12。 include using namespace st在下面程序的横线处填上适当的语句，使该程序的输出为12。include ＜iostream＞using namespace std;class Base{public:int a;B．ase(int i){a=i;}};class Derived: public Base{int a;public:D．erived(int x): Base(x),b(x+l){}void show(){

[主观题]（12）有以下程序，请在 (12) 处填写正确语句，使程序可正常编译运行。#include <stdio.h>(12) ;main(){ double x,y,(*p)();scanf("%lf%lf",&x,&y);p=avg;printf("%f/n",(*p)(x,y));}double avg(double a,double b）{ return((a+b)/2);}

[试题]在下面的程序的横线处填上适当的语句,使该程序的输出为12。 include using namespace在下面的程序的横线处填上适当的语句，使该程序的输出为12。include＜iostream.h＞using namespace std;class Base{public:int a,b;B．ase(int i){a=i;}};class Derived:public Base{int a;public:D．erived(int x):Base(x),b(x+1){};void show(){

[试题]在下面程序的横线处填上适当的语句,使程序执行后的输出结果为ABCD。 include using nam在下面程序的横线处填上适当的语句，使程序执行后的输出结果为ABCD。include＜iostream＞using namespace std;classA{public:A．(){cout＜＜'A';}};class B:______{public:B．(){cout＜＜'B';}};class C:______{public:C(){cout＜＜'C';}};class D:pub

[单选题]下列语句序列执行后，ch1的值是（）。char ch1=’A’，ch2=’W’;if（ch1+2

[单选题]下列程序中横线处正确的语句是()。includeusing namespace std;class TestClass{publi下列程序中横线处正确的语句是( )。 #include＜iostream＞ using namespace std; class TestClass { public: void fun(){cout＜＜"TestClass::fun"＜＜end1;} }; class TestClass1:public TestClass { void fun() { ____

[单选题]设有以下语句：char ch1,ch2; scanf(”%c%c”,&ch1,&ch2);若要为变量ch1和ch2分别输入字符A和B，正确的输入形式应该是A．)A和B之间用逗号间隔B．)A和B之间不能有任何间隔符C．)A和B之间可以用回车间隔D．)A和B之间用空格间隔