. Which of the following is true'? A: . a compulsory VHF-DSC radiotelephone installation must be daily tested without radiation. B: a compulsory VHF-DSC radiotelephone installation must be annually tested without radiation C: a compulsory VHF-DSC radiotelephone installation must be monthly tested without radiation. D: a compulsory VHF-DSC radiotelephone installation must be weeklv tested without radiation.

3. Which of the following sentence is right? A: The goal is to learn their risk of thyroid cancer the extent to which radiation may increase. B: The goal is to learn the extent to which radiation may increase their risk of thyroid cancer. C: The goal may increase their risk of thyroid cancer is to learn the extent to which radiation. D: The goal is to learn the extent to radiation which may increase their risk of thyroid cancer.

以下哪一项表达最为准确？? Both bombs produce the same three effects: heat, blast, and radiation,;the first of which usually causing;the most fatalities.;|Both bombs produce the same three effects: heat, blast, and radiation, the first of which usually causes the most fatalities.;|Both bombs produce the same three effects: heat, blast, and radiation, the first of;them usually causes the most fatalities.;|Both bombs produce the same three effects: heat, blast, and radiation. The first of which usually causes the most fatalities.;

The accumulation of greenhouse gases (GHGs) causes global warming by letting sunlight into the atmosphere as _______. Then, when the earth re-radiates the heat back to space, the gases trap the energy in the form of outgoing ______. A: visible light, ultraviolet radiation B: infrared radiation, ultraviolet radiation C: ultraviolet radiation, infrared radiation D: infrared radiation, radio waves

radiation

The light emitted by the LED is incoherent light, and its basic principle is . A: stimulated absorption B: spontaneous radiation C: stimulated radiation D: spontaneous radiation

the of nuclear radiation

 radiation sterlization

What is the author's main purpose in writing this passage A: Emphasizing the importance of protection from radiation. B: Solving the mystery about radiation. C: Discussing the cause of cancer. D: Introducing the nuclear power.

reflecting<br/>radiation ______ 。