蜂鸣器

tā àn fēng míng qì kāi mén rè qíng de yíng jiē tā men

她按蜂鸣器开门，热情地迎接他们。

She buzzed them in and greeted them warmly.

fàn zuò hǎo shí fēng míng qì huì fā chū xiǎng shēng

饭做好时蜂鸣器会发出响声。

The buzzer rang when the meal was ready.