a) A preposition is where or when something is.
b) A contracted apostrophe word is when an apostrophe is used in place of a letter or letters to make the word shorter.
can not -> can't do not -> don't will not -> won't
c) A word family is a group of words containing the same group of letters. Can you think of a group of words that all have "care" in it?
Here is an example of a different word family.