请大佬帮我看看我的程序，说是Battery nanfu=new Bettery(100);和Radio.openRadio(nanfu);没有定义类型

Question

class Battery{
int electricityAmount;
Battery(int amount){
electricityAmount=amount;
}
}class Radio{
void openRadio(Battery battery){
battery.electricityAmount=battery.electricityAmount-10;
}
}
public class E7 {
public static void main(String args[]){
Battery nanfu=new Bettery(100);
System.out.println("南孚电池的储存电量是："+nanfu.electricityAmount);
Radio radio=new Radio();
System.out.println("收音机开始使用南孚电池");
Radio.openRadio(nanfu);
System.out.println("目前南孚电池的储存电量是："+nanfu.electricityAmount);
}
}

Answer 1

Battery nanfu=new Battery(100);
...
radio.openRadio(nanfu);