1. Which of the following detectors

1. Which of the following detectors are based on the charges or light principle? A. Smoke detectors B. Heat sensors C. Temperature rising sensors D. Flame detectors2. In general, _______ of fire detectors are fitted on the compartment being protected. A. one type B. two types C. three types D. four types3. Within engine room,________ sensors are arranged certainly. A. smoke B. heat C. temperature rising D. flame4. Which of the following statements is true? A. The more types of fire detectors are fitted on the space being protected, the more possible it is to avoid fire hazards. B. Flame detectors are based on the light principle of fire detection. C. Cigarette smoking will always cause fires. D. A test canister implies it is unnecessary to sample fumes for detection fire.