Please choose the correct ending to complete the given sentence: Education and Communications: [header] How to make a leyden jar [title] Choose a jar. [step] You have to be careful about what materials you use to construct your leyden jar. The material must serve as an insulator between the inner charge (+) and the outer charge (-).

Ending1: There are two types of jars, the hardy and the non-hardy. The hardy jars contain only the same thing as the non-hardy ones, only you have to poke holes through them to separate them from each other. Ending2: Dense materials such as styrofoam and glass are best used for leyden jars. Instead, invest in cheap glass and metal jars that will adhere to temperature-controlled environments or those that are made at higher temperatures to preserve keratin and other flavorings. Ending3: Choose a glass jar or a plastic bottle with a lid. [substeps] If possible, get a big jar or bottle, such as one that holds 0.5 to 1 gallon (1.9 to 3.8 l). Ending4: The inner charge is achieved via substances like hydrogen peroxide and baking soda together. [title] Layer pieces of paper or a piece of cardboard, and trace your jar on the cardboard or cardboard.

Answer format: ending1/ending2/ending3/ending4