The eyes may be injured by
A: Mechanical impact
B: UV light
C: Radiation
D: Chemical
A: Mechanical impact
B: UV light
C: Radiation
D: Chemical
举一反三
- What kind of wave does ultrasound belong to and has certain radiation? A: Electromagnetic wave B: Mechanical wave C: Particle wave D: Light wave
- 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 light emitted by the LED is incoherent light, and its basic principle is . A: spontaneous radiation B: stimulated absorption C: stimulated radiation D: spontaneous absorption
- Which<br/>kind of physical hazard causes the welding flash? () A: Light B: Ionizing radiation C: Ultraviolet radiation D: Vibration
- earlite is a kind of ( ). A: Metal compound B: Solid solution C: Mechanical mixture D: Chemical compound