Optical-based smoke alarms use light instead. They are slightly better at detecting the large smoke particles created by slow, smouldering fires. When such particles enter a chamber in the device, they scatter light from a small light source, which is then picked up by a photoelectric sensor.
为80岁母亲手机设三重“防骗墙”失效，“技术男”把亲身经历告诉大家引以为戒
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What are Moon phases?According to NASA, the Moon takes about 29.5 days to orbit the Earth. Over the course of this period, it moves through eight recognisable phases. While the same side of the Moon always faces us, the amount of its surface lit by the Sun changes as it continues along its path. The shifts in sunlight create the different appearances we see from Earth, ranging from a fully illuminated Moon to a thin sliver or near darkness. The eight phases are:。51吃瓜对此有专业解读
Katherine and Martin Short pictured together in 2006
Still, it is much closer Modern English than we might think.