尝试使用新的LearnStreet在线教程学习Ruby。试图通过他们的问答系统获得帮助，但似乎没有人回答他们。"Canyounowimplementthewithdraw!methodonaccountobject,whichtakesoneparameteramountandreducesthebalancebythespecifiedamount?Afterdefiningthemethod,goaheadandwithdraw100dollarsfromtheaccountandcheckthebalance."是题和我得到的两个提示"Hint1Thecode@balance=@