Air Pollution Control Engineering Why should we know that? It's very important for us to know how the atmosphere moves everyday,if we want to find some available ways to solve the air pollution. Hover Fly There is something interesting:hovering is really different from flying, because if you want to hover,you must keep agitating your wings,but if you are flying,you can feel the real freedom. But it is impossible for angle to fly at dawn or cloudy day.It is also very dangerous for people to glide in that situation.Do you know why? PDF文件使用"pdfFactory Pro”试用版本创建m,fineprint.com,c里Why should we know that? It’s very important for us to know how the atmosphere moves everyday, if we want to find some available ways to solve the air pollution. Hover Fly There is something interesting: hovering is really different from flying, because if you want to hover, you must keep agitating your wings, but if you are flying, you can feel the real freedom. But it is impossible for angle to fly at dawn or cloudy day. It is also very dangerous for people to glide in that situation. Do you know why? There is something interesting: hovering is really different from flying, because if you want to hover, you must keep agitating your wings, but if you are flying, you can feel the real freedom. But it is impossible for angle to fly at dawn or cloudy day. It is also very dangerous for people to glide in that situation. Do you know why? Air Pollution Control Engineering PDF 文件使用 "pdfFactory Pro" 试用版本创建 ÿwww.fineprint.com.cn