line busy tone

例句：

1. 1.She's on a busy line at the bank.
   她在银行电话线很忙。
2. 2. The busy tone of his voice made it clear that he was in a hurry.
   他急促的语气表明他急着要办某事。
3. 3. The line was so busy that we had to wait for over an hour before we could speak to someone.
   这条线路非常繁忙，我们等了一个小时才联系到人。