Final answer:
Venting food covers during microwave cooking serves two purposes: to release steam and allow even heating.
Step-by-step explanation:
Venting food covers during microwave cooking serves two purposes: 1) to release the steam that builds up inside the container, preventing it from causing an explosion or splattering, and 2) to allow the microwaves to penetrate the cover and evenly heat the food. This helps to prevent hot spots and ensure that the food is cooked thoroughly.