Lu Ban was a famous inventor. | He created the Luban Lock to see how clever his son was. | It took his son a whole night to put it back. |
One day, Lu Ban cut his hand on a leaf. He came up with a good idea. He invented the saw. | Watching his mother making a quilt (被子), Lu Ban created the ink line to mark a straight line on wood to saw it properly. | The plane was invented to make flat surfaces (平整的表面) on the wood. |
Choose the best choice from A, B or C according to what you read.