题目

阅读理解Fahad Azad, anengineer in India, invented a robot named DuctBot. The toy-car sized DuctBotmeasured 23 centimeters in length, 19 centimeters in width and 9 centimeters inheight and weighed just two kilograms. The robot is designedto snake through dark, narrow air conditioning ducts(管道) and clean them. A pair of LEDs fitted on the robot light up thedirty scenery, so it can be captured (抓拍) by a camera. In order to control itmore easily, Mr. Azad chooses to fix DuctBot on wheels. The robot can clean offlots of dirt, as well as dead pigeons and insects. Keeping indoor air in go生男生女是由母亲决定的。（____）