接口无法实现的小问题。。。。分数不多，请大侠帮忙！！

Question

这是《C#高级编程》里的一个例子，官方网站太慢上不去，只能在这里提问了Bank.cs：    public interface IBankAccount
    {
        void PayIn(decimal amount);
    }    public class GoldAccount : IBankAccount
    {
        private decimal balance;
        public void PayIn(decimal amount)
        {
          //........
        }
    }    public class SaverAccount : IBankAccount
    {
        private decimal balance;
        public void PayIn(decimal amount)
        {
            //......
        }
    }    //派生的接口    public interface ITransferBankAccount : IBankAccount
    {
        bool TransferTo(IBankAccount destination, decimal amount);
    }
    public class CurrentAccount:ITransferBankAccount
    {
        private decimal balance;
        public void PayIn(decimal amount)
        {
            //.....
        }
        public bool TranferTo(IBankAccount destination, decimal amount)
        {
　　　　　　//代码略～
        }//问题就在这里了。。
    }Program.cs:
        static void Main(string[] args)
        {
            IBankAccount venusAccount = new SaverAccount();
            CurrentAccount jupiterAccount = new CurrentAccount();
            venusAccount.PayIn(200);
            jupiterAccount.PayIn(500);
            jupiterAccount.TransferTo(venusAccount, 100);//这里...
            Console.WriteLine(venusAccount.ToString());
            Console.WriteLine(jupiterAccount.ToString());
            Console.ReadLine();
        }代码简略了一些，问题不太，主要问题是编译时出现以下问题：
“BankAccount.CurrentAccount”不会实现接口成员“BankAccount.ITransferBankAccount.TransferTo(BankAccount.IBankAccount, decimal)”
问题出在哪呢？谢大侠帮忙解决一下

Answer 1

public bool TranferTo(IBankAccount destination, decimal amount)
少个s