Please choose the correct ending to complete the given sentence: Education and Communications: [header] How to be safe when using a chemistry lab [title] Be smart about chemicals and the dangers they pose. [step] Some chemicals are harmless; others can kill you! Until you are familiar with the chemicals you are using in the lab, always ask an instructor for help. There are a few basic points about chemical safety to bear in mind : [substeps] Never mess with an unlabeled chemical.

Ending1: Getting toxic shock or heart attack could result in death. [title] Begin using the theoretical spaces of the lab. Ending2: Find an academic chemistry lab that is clean. It should be clean and free of chemicals and other toxic items. Ending3: Always sweep it under the microscope using a lint-free material. Always note those parties that are coming into the lab. Ending4: It may be corrosive and dangerous to your skin, and mixing it with other chemicals could produce toxic fumes or even an explosion. Know the difference between an acid and a base.

Answer format: ending1/ending2/ending3/ending4