The device comprises an electric source, an alarm part, an acoustic and optical part and an outer shell.

该装置由电源、报警部分、音响灯光部分及外壳组成！

youdao

The device comprises an electric source, an alarm part, an acoustic and optical part and an outer shell.

该装置由电源、报警部分、音响灯光部分及外壳组成！

youdao