DFA exercises

Write DFAs for the following languages..

1. The language of strings over the alphabet { a, b } beginning and ending with a and having exactly one b somewhere in between.
2. The language of strings over the alphabet { a, b } with an even number of as and an even number of bs.
3. The language of strings over the alphabet { a, b, c } with exactly two as, exactly one b, and any number of cs.
4. The language of strings over the alphabet { a, b, c } containing any number of the following substrings and nothing else: abbc, acb, aabacc.