写出下面程序的运行结果。 #include <iostream> using namespace std; class Base { public: void Who( ){cout<<"class Base"<<endl;} }; class Derived1:public Base { public: void Who( ){cout<<"class Derived1"<<endl;} }; class Derived2:public Base { public: void Who( ){cout<<"class Derived2"<<endl;} }; int main( ) { Base obj1,*p; Derived1 obj2; Derived2 obj3; p=& obj1; p->Who(); p=& obj2; p->Who(); p=& obj3; p->Who(); obj2.Who(); obj3.Who(); return 0; } ______ ______ ______ ______ ______

标准以太网指的是 ( ) A: 10 BASE 5 B: 10 BASE 2 C: 10 BASE T D: 100 BASE T

给出下面的代码段 public class Base{ int x, y; static int z; public Base(int a,int b)<br/>{ x=a; y=b; } } 以下代码错误的是?(). A: Base b=new Base(); <br/>b.z=10; B: Base b=new Base(1,2); <br/>b.z=10; C: Base.z=10; D: Base b=new Base(1,2);<br/>b.x=2;

（6-2）定义如下Base类，能在(1)处正确调用Base的构造方法。 class Base{ int x,y; Base(int x){} Base(int x,int y){ //(1)调用Base的构造方法 } }

以下代码调试结果 class Base {} class Sub extends Base {} public class CEx{ public static void main(String argv[]){ Base b = new Base(); Sub s = (Sub) b; } }

如何能使程序调用Base类的构造方法输出"base constructor"; class Base{ Base(int i){ System.out.println("base constructor"); } Base(){  } } public class Sup extends Base{ public static void main(String argv[]){ Sup s= new Sup(); //One } Sup() { //Two } public void derived() { //Three } }

The composition of<br/>backbone of polynucleotides includes () A: base and pentose<br/>sugar B: base and<br/>phosphate C: base and base D: pentose sugar and<br/>phosphate E: pentose sugar and<br/>pentose sugar

以下运算符优先级排列正确的是（ ） A: *= &amp;&amp;！= % B: *= % &amp;&amp;！= C: %！= &amp;&amp; *= D: &amp;&amp;！= % *=

若图中直线，，的斜率分别为，，，则(　　) A: $amp;$amp; B: $amp;$amp; C: $amp;$amp; D: $amp;$amp;

下面程序段运行结果是____。 A: B: &amp;˽&amp;˽&amp;* C: D: ˽&amp;˽&amp;˽&amp;˽* E: F: &amp;&amp;&amp;* G: H: ＆˽*˽˽