a tip to start off - pls number your pics for better C&C
The shots are a bit boring, I mean to say that nothing exciting about the subjects or the composition.
Having said that,
1 is good, different lighting/angle?
3 a different angle would have made this one great, but nice color nevertheless
4 lighting makes this very dull.
Play around and try to get that bit of drama into your shots. A pic should tell a story or evoke some interest. If you can manage that, great!