下列代码的运行结果是: class Cell{ public int row; public void drop(){ row+=7; } } public class Tetromino extends Cell{ public void drop(){ row-=3; } public void drop(int x){ drop(); super.drop(); row*=x; } public static void main(String[] args){ Tetromino tetrom= new Tetromino(); tetrom.drop(2); System.out.println("row is:"+tetrom.row); } }