关于太阳黑子的正确叙述是（   ）

    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.

用一个平面去截一个几何体，若截面是长方形，则该几何体可能是____ （写三个）．