How would you use a radio or a telephone if you had no electricity or batteries? This 1 bothered (使烦恼) British inventor Trevor Baylis. So in 1996, he 2 a wind-up (装有发条的) radio. It doesn't need any 3 or batteries. You wind it up by hand. It plays for about an hour. Then, you wind it up 4, and it plays for another hour. Today it's made in South Africa.

    Then in 1999, Baylis invented a mobile telephone that is powered by 5.The shoes have a small battery that is powered when you 6. This battery is connected to a mobile phone.

    These two simple inventions can bring 7 communications to all parts of the world. Baylis doesn't have a university degree in engineering. In 8, he left high school before graduating. He just loves 9 things to help people. He never knows when 10 will come to him. The idea for the telephone came to him in a dream.

如图是利用无人小飞机进行航拍，则在地面操控者进行以下操作时能把无人机看成质点的是（   ）

小明在网络中看到镁是航空工业的重要材料，欲通过实验探究镁的性质．

（2011•滨州）下列四幅地形剖面示意图，能正确表示我国地势变化的是（　　）