下列程序中需要清理动态分配的数组，划线处应有的语句是______。
#include＜iostream, h＞
class person int age, tall;
public:
person() age= 0; tall= 40; cout＜＜"A baby is born. "＜＜end1;
person(int i) age=i, tall=40, cout＜＜"A old person. "＜＜end1;
person(int i, int i) age = i; tall = j; cout ＜＜" a old person with tall. "＜＜
end1；
～person( ) cout＜＜" person dead. "＜＜end 1；
void show()
cout＜＜"age= "＜＜age＜＜" ,tall= "＜＜tall＜＜end1;
;
void main() person * ptr;
ptr = new person[3];
ptr[0]=person ( )
ptr[1]=person(18);
ptr[2]=person(20,120);
for(int i=0;i＜3; i++)
ptr[i]. show( );
______