短文改错
| Your teacher of maths has taught you when to | 1.__________ |
| find the centre of a circle! It takes sometime. | 2.___________ |
| Here is a simple method.Put the corner of a sheet of paper in | 3.___________ |
| the circumference (圆周) of the circle, | 4.___________ |
| then make points A and B which the sides of the paper | 5.____________ |
| across the circle.You may be sure that points | 6.____________ |
| A and B mark the end of a diameter (直径). | 7.___________ |
| To draw it, then repeat this process at a | 8.__________ |
| different place to get other diameter. | 9._______ |
| You will find the centre where two lines cross. | 10._________ |