Write the next sentence in the following story.

How to prevent avocados from browning
Look for avocados that are semi-soft in the store.
They will be able to be cut open and used that day. If you're planning not to use them right away buy firmer avocados and let them sit on your counter for a few days to ripen up.
If they are ripening too quickly, refrigerate them. Slice your avocado length-wise, once you're ready to use it.