If the caller has to listen to a recording before speaking to the reservation agent, this should not last more than 20 seconds.

如果来电者在与预定部通话前须听等候音乐，不应该持续超过20秒。

youdao

I called the toll-free reservation number for a major hotel chain. The reservation agent was very helpful, after I got through the long phone tree.

我拨通了一家有名的酒店连锁的免费预订电话。经过长长的一系列电话指示，我终于接通了预订的电话，他给了我很大的帮助。

youdao

Agent: Certainly. Do you have a reservation?

经办人：当然可以。你预订了吗？

youdao

Instead, they must call the airline or get an airport agent to add a lap child to their reservation.

WSJ: Flying With Little Children? Go to the Back of the Plane