Please choose the correct ending to complete the given sentence: Relationships: [header] How to build a simple birdhouse [title] Cut the wood to the sizes needed. [step] Cut out 7-9 6x6 pieces of wood, measuring 2 cm-5 cm thick and thin, depending on your intended size. These form the 4 walls, the 1 floor and the 2 roof pieces.

Ending1: Do not use plywood, it may tear. [substeps] Mark the measurement on the wood with a marker/pencil. Ending2: Nail these to the bottom of the box and around all 4 sides, making sure that they're even. Keep repeating this until you have your desired size. Ending3: Use appropriate tools to cut out all eight layers of wood. [substeps] If you've chosen to form a birdhouse structure, you'll need approximately 8 inches (20 cm) of wood. Ending4: [title] Using a compass, draw a circle on one of the squares. [step] Depending on the bird you're hoping to encourage to stay, the circle should be of the size it can adequately fit into.

Answer format: ending1/ending2/ending3/ending4