例句：

　　The burglar alarm should be professionally installed.

　　防盜警報應當由專業人員安裝。

　　He opened the door and came face-to-face with a burglar.

　　他打開門和竊賊打了個照面。

　　The main thing to remember is to switch off the burglar alarm.

　　最要緊的是記住關掉防盜報警器的開關。