填空题 阅读以下说明和Java程序，将应填入{{U}} (n) {{/U}}处的字句写在对应栏内。
[说明]
下面程序输出一个矩形面积，以及矩形区域上的假想的作物产量。
[Java程序]
public class MainJava {
public static void main(String[] args){
Lot_size small=new Lot_size();
Lot_size medium=new Lot_size();
small.set(5,5,5，25);
medium.set(10,10,10,50);
System.out.println("For a small lot of area"
+small.get_area()+"/n");
System.out.println("the actual crops are $"
+small.get_data2()+"/n");
System.out.println("and ideal crops are $"
+small.get data()+"/n");
System.out.println("For a medium lot of area"
+medium.get_area()+“/n”)；
System.out.println("the actual crops are $"
+medium.get_data2()+"/n");
System.out.println ("and ideal crops are $"
+medium.get_data()+"/n");
}
}
class Crop_assessment{
private int actual_crop;
private int ideal_crop;
public void set(int in_actual,int in ideal){
actual_crop=in_actual;
ideal_crop=in_ideal;
}
public int get_actual_crop(){return {{U}}(1) {{/U}};}
public int get_ideal_crop()(return {{U}}(2) {{/U}};}
}
class Lot_size{
private int length;
private int width;
private Crop_assessment crop={{U}} (3) {{/U}};
public void set(int 1,int W,int a,int i){
length=1;
width=W;
crop.set(a,i);
}
public int get_area(){return length^*width;}
public int get_data()freturn{{U}} (4) {{/U}};}
public int get_data2()(return{{U}} (5) {{/U}};}
}