电话占线，我稍后再打。

The phone ___line is busy; I'll call back later.

恐怕您的电话线路已被断开，因为您上一张账单未付。

I'm afraid your ___line has been disconnected because your last bill hasn't been paid.

请稍等，别挂断电话，我去看看她是否可用。

Please hold the ___line while I check if she's available.