他们应该明白不同报警信号的意义。（）A、They should be clear about all fire-fighting equipment..B、They should be understood about the meaning of the different alarm signals.C、They should be clear about all life-saving equipment.D、They should be clear about the meaning of the
题目
他们应该明白不同报警信号的意义。（）
- A、They should be clear about all fire-fighting equipment..
- B、They should be understood about the meaning of the different alarm signals.
- C、They should be clear about all life-saving equipment.
- D、They should be clear about the meaning of the different alarm signals.