Eat
Ate would be past tense but since you are still doing it it is eat
My general description of such a person is someone, anyone who encourages and inspires others to appreciate the positive qualities of life, such as, good hygiene, health, gentleness, contentment, and safety. These qualities may seem dull or cliche to many people, but anyone who practices these qualities and appreciates these qualities does find life much more rewarding as opposed to so many people who destroy their life with addictions, negative attitudes, slovenliness, criminal activity, despair etc.
I believe the linking verb is “will”. It’s linking the subject “the United States of America” and the predicate “be 300 years old!”
