超星 - 面向对象（下）

单选题

在java中，已定义了两个接口B和C，要定义一个实现这两个接口的类，以下语句正确的是（）

A. interface A extends B,C
B. interface A implements B,C
C. class A implements B,C
D. class A implements B,implements C

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单选题

类间的继承关系是（）

A. 单重的
B. 多重的
C. 既可以单重又可以多重
D. 不能继承

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单选题

阅读下面的程序，其中正确的是（）class person {String name;String nickName;public person(String a, String b) {name=a;nickName=b;}public String toString() {return name+" nickName="+nickName;}}public class employee extends person {String rank;public employee (String a, String b, String c) {super(a, b);rank=c;}public String toString(){return name+" nickName="+nickName+" rank="+rank ;}public public static void main(String[] args) {person one=new person("Wang", "Zhang");person two=new employee("Bob", "Tom", "manager");employee three =new employee("Jack", "David", "CEO");System.out.println(" one is "+ one.toString());System.out.println(" two is "+ two.toString());System.out.println(" three is "+ three.toString());}}

A. 编译时会出现错误
B. 运行时会出现错误
C. 运行结果是： one is Wang nickName=Zhang two is Bob nickName=Tom rank=manager three is Jack nickName=David rank=CEO
D. 运行结果是： one is Wang nickName=Zhang two is Bob nickName=Tom three is Jack nickName=David rank=CEO

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单选题