This is a test of commonsense. Complete the next sentence:

How to keep green onions fresh
Fill a glass or tall jar with 1-2 inches (2.5-5.1 cm) of water.
Use a glass or jar that is heavy on the bottom so that it easily stays upright. The water should be cold or room temperature, but not warm.
The glass or jar should be tall enough so that it can keep the green onions upright. For example, a pint glass or a large canning jar works well.