Please choose the correct ending to complete the given sentence: Health: [header] How to clean your retainer [title] Rinse off the retainer with warm or cold (not hot) water. [title] Place the retainer in a shallow cup, big enough to fully hold it. [title] Pour vinegar into the cup until the retainer is fully submerged.

Ending1: [title] Squirt some removable metal adhesive, such as acrylic or polyurethane, onto the retainer. [title] Secure the retainer with some foam sealants, if desired. Ending2: [title] Let it sit for 2 to 5 minutes. [step] Longer is not necessary, as the vinegar could begin to degrade the plastic. Ending3: [step] Alternatively, you can warm the retainer instead. [title] Strain out excess water using a strainer or a fine strainer. Ending4: [step] Tea tree oil and camphor can also be used. [title] Place the retainer in the bag.

Answer format: ending1/ending2/ending3/ending4