the only thing you can do is pay the fee to recover the serv

the only thing you can do is pay the fee to recover the service .句中的为什么不是is to pay the fee
the only thing you can do is pay the fee to recover the service .中文意思：你唯一能做的就是缴费恢复你的服务.句中的为什么不是is to pay the fee?为什么能直接是is pay呢?这样不是2个谓语了吗?书中的印刷应该没错的,因为我听录音带里面的也是这么读的.请高手指教,