Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to build a dog ramp [title] Calculate how long your dog ramp needs to be. [step] If you need the dog ramp to cover a set of steps, measure the distance from the bottom of the steps to the top and add 4 inches (10.16 cm). [title] Place two 2-inch by 2-inch (5.08 cm by 5.08 cm) pieces of lumber on a firm surface.

Ending1: [step] Measure the desired length of the ramp. Mark the length on both boards with a pencil. Ending2: [step] Make sure one piece stays up, and the other stays down. [title] Measure the length, weight, and height of the deck. Ending3: [step] Make sure that the lumber is level. [title] Place one leg under the other and place two pieces of 2-inch by 1-inch lumber together. Ending4: [step] Using minimum width from two pieces of lumber, cut four long strips of lumber. Hold the strips perpendicular to each other and make each cut approximately equal in length.

Answer format: ending1/ending2/ending3/ending4