阅读以下说明和C++程序，将应填入(n)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。

[C++程序]

include ＜iostream.h＞

class crop_assessment

{

int actual_crop;

int ideal_crop;

public:

void set(int in_actual,int in_ideal)

{

actual crop=in_actual;

ideal_crop=in_ideal;

}

int get_actual_crop(void){ (1) ;}

int get_ideal_crop(void){ (2) ;)

};

Class lot_size

{

int length;

int width;

(3) crop;

public:

void set(int 1,int w,int a,int i)

{

length=1;

width=w;

crop.set(a,i);

}

int get_area(void){return length*width;}

int get_data(void){return (4) ;}

int get_data2(void)freturn (5) ;}

}

int main()

{

Los_size small，medium;

small.set(5,5,5,25);

medium.set(10,10,10,50);

cout＜＜"For a small lot of area"＜＜smallget_area()＜＜“\n”;

cout＜＜"the actual crops are$"＜＜small.get_data2()＜＜"\n";

cout＜＜"and ideal crops are$”＜＜small.get_data()＜＜"\n";

cout＜＜"For a medium Lot of area"＜＜medium.get area()＜＜:\n”;

cout＜＜"the actual crops are$"＜＜medium.get_data2()＜＜"\n";

cout＜＜"and ideal crops are$"＜＜medium.get_data()＜＜"\n";

return 0;

}