For the most part these pics are suffering from compositional problems with the exception of the tire photo which i also agree is the best one.
The flower pics would have been better had you waited for more even light on an over cast day... the light is just too harsh and the central placement of the flower in #2 is a detriment.
The couple seated on the bench.... thir heads are cut off.... thats not good.
The couple walking on the tracks... their top half is cut off. If they are the subject they should all be in the frame... if it was an artistic decision to cut them off ask yourself.. Does it benefit the subject?The dead space on the bottom could be removed as the subject isnt the tracks themselves but the people walking along the tracks.
The bird shots.... firs and foremost... invest in a circular polarizer filter. It helps to remove window glare.
The second bird photo ... what is the subject? her or the birds? if it is her you cut her head off and if it is the birds you cut the birds tails off.... the focus of the picture is not clear.
the second to last flower shot could use a bump in contrast and possibly would be better if you were closer to the subject.
Anyway.. i am just giving so much critique because I believed you posted these with the intention of getting better and not just as snapshots.