Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to make a sanding block [title] Select a wood block. [step] You can use a small block of off-cut wood retrieved from the scrap pile, provided it's the right shape. A rectangle is the optimal shape because it's easy to hold and covers a good area when sanding.

Ending1: Choose something that's the same color or different size as your sanding block. [substeps] You can use blocks made from the same material, purchased or cut yourself, or create your own from the block of plywood or wood. Ending2: [substeps] Therefore, you should expect the back of the block to be 3-4 inches (7.6-10 cm) in size. If you've never sanded a wooden block before, bring the block of off-cut wood to the local hardware store. Ending3: If needed, cut a piece of ordinary wood into a rectangle of a size suitable to hold in your hand (around 2 " x 4 "). [title] Fold the piece of sandpaper over the sanding block. Ending4: Tall blocks are ideal since they give when they are close together, and have the added benefit of providing a less bulky block to protect your home from the elements. [substeps] The exact thickness measurement for a wood block of moderate thickness and similar density will differ, but generally more than 4 feet would be an ideal size.

Answer format: ending1/ending2/ending3/ending4