Please choose the correct ending to complete the given sentence: Finance and Business: [header] How to document your invention [title] Buy a bound notebook. [step] Despite technological advances, the best way to document your invention remains hand-writing details regarding your idea, descriptions, and tests on paper in a bound notebook. [substeps] Look for something with a hard cover, and pages that are sewn in.

Ending1: A bound notebook may not have slats, which may slow down recording or compromise color or quality production. The sheet of paper that the notebook contains must also have a cover, and be sturdy enough that it holds all of your writing. Ending2: This makes it more difficult for a later challenger to argue that you added something after the fact. Some of these books have blank pages, while others include lines or grids. Ending3: If the cover is made of a stronger material, like leather or other paper, take into account the texture. Rigid pages will be difficult to break into or to roll. Ending4: The paper you purchase should have a high, flat edge and thick pages. Only put electronic papers in a notebook, since they should be bound to plastic.

Answer format: ending1/ending2/ending3/ending4