Please choose the correct ending to complete the given sentence: Home and Garden: [header] How to remove polyurethane [title] Create cross-ventilation. [step] Generally, you need chemicals to remove polyurethane. Because these chemicals are often harsh, you need good ventilation to protect yourself.

Ending1: If you can, go outside to work. If you're working on floors, create cross-ventilation to help keep you safer. Ending2: [substeps] The easiest and simplest way to create a cross-ventilation patch is using a small, cloth-like rain balloon. Cover the top of the balloon with fencing material. Ending3: Get everything figured out before tackling polyurethane. Make sure to test everything you can on a non-stone surface. Ending4: To make a small bottle of polyurethane, mix equal parts ammonia and water. Swish the solution around until a film forms.

Answer format: ending1/ending2/ending3/ending4