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.
Мир Российская Премьер-лига|19-й тур
，推荐阅读同城约会获取更多信息
Support the Guardian: theguardian.com/sciencepod
这类场景也很能体现 Expert 的定位，它尝试把一整段专业工作流程产品化，从增强单次问答的模式里彻底跳了出来。