In small lamps, all the air is pumped from the glass bulb, forming a vacuum, which prevents the white-hot filament from burning away.
在小照明灯中，所有的空气都从灯泡中抽出，形成真空，以防炽热的灯丝被烧毁。
A glass bulb filled with finely shredded aluminum or magnesium foil that is ignited by electricity to produce a short-duration high-intensity light flash for taking photographs.
