在负的外部性的例子中，有效的政府政策是（）。

给出以下语句：

class Parent{

String one,two;

public Parent(String a,String b){

one=a;

two=b;

}

public void print(){System.out.println(one);}

}

public class Child extends Parent{

public Child(String a,String b){

super(a,b);

}

public void print(){

System.out.println(one+"to"+two);

}

public static void main(String arg[]){

Parent P=new Parent("south"，"north");

Parent t=new Child("east","west");

P.print();

t.print();

}

}

下面的运行结果中正确的是______。

A．在编译时出错

B．south

east

C．south to north

east to west

D．south to north

east

E．south

east to west

program.

A. publics will get information from

B. television may not get information from

C. the parent will be punished by

D. the child will be saved by

A、instantiate a child

B、instantiate a parent

C、instantiate a child instantiate a parent

D、instantiate a parent instantiate a child

A．parent child child

B．parent child parent C. parent child D. 编译错误

A．publics will get information from

B．television may not get information from

C．the parent will be punished by

D．the child will be saved by

Which of the following is INCORRECT？

A．Self-sufficiency is valued in the US.

B．If one child is unwilling to be responsible for his/her parent, he/she may be hated by his/her brothers or sisters.

C．Some children think that sending their parent to a convalescent hospital can be justified.

D．Actually, all children can contribute an equal share to the cost of their parents care.

All of the following can be inferred form. the passage except that ______.

A．many developed nations suffer from the problem of a rapidly aging population

B．the family-planning policy meets more difficulty in the countryside than in cities

C．the increasing number of aged people is a result of the reduced birth-rate

D．in the year of 2010 each child will have to look after one parent

A、one parent has died.

B、one parent is divorced.

C、one parent is separated.

D、any or all of the above