Please choose the correct ending to complete the given sentence: Food and Entertaining: [header] How to use a milk frother [title] Buy fresh milk. [step] Check the expiration date of milk when you buy it at the store. Choose milk that is farther from its expiration date.

Ending1: Older milk has more glycerol, a natural compound that makes it harder for frothed milk to hold its bubbles. [title] Use skim milk if you're new to frothing. Ending2: To ensure that you are getting the right product, look for cans that have a seal from the expiration date listed on them. Often, these cans will be marked as " canned, " " mixed, " or " open. Ending3: In some places, you can purchase fresh milk without any time in the store. Dairy and non-dairy milk products all have age-appropriate expiration dates, so you don't need to worry about them when shopping for a regular frother. Ending4: Some dairy items may contain expired milk, which is more bitter than fresh. Make sure to choose plain, unflavored milk.

Answer format: ending1/ending2/ending3/ending4