Please choose the correct ending to complete the given sentence: Health: [header] How to survive a gas attack [title] Be aware of any yellow-green gas floating around with the strong smell of bleach. [step] Some soldiers in wwi described it as pepper and pineapple. If you are exposed to chlorine gas, you may have trouble breathing or seeing and will feel a burning sensation.

Ending1: It might be the worst case scenario ever, and it's possible you could be injured. Before you fall, stand as close to the gas's source as possible. Ending2: Keep your eyes closed, and don't open them when emergency personnel arrive (or in several hours). [title] Know that exposure to so much chlorine promotes lung disease and cancer. Ending3: [title] Move quickly into an area with clean air in order to minimize exposure to the gas. [substeps] If indoors, exit the building as quickly as possible. Ending4: [title] Know that air is entering the area from inside the building. [step] There will be people in this area who can help you block each of the breathing holes so all the air can escape.

Answer format: ending1/ending2/ending3/ending4