Thanksgiving is a day everyone gives thanks for when the native Indians helped the Europeans. Labor Day is being grateful for our American soldiers.
Something like that.
When Katy plays a baseball she has to run to a base to try to make a full home run on 4 bases
It looks good.
You did a nice job being descriptive and your grammar looks fine.
B. Does not. A prefix won't change the root word. If you take a prefix off of a root word the root word will always stay the same.
