The rule of thirds is a powerful compositional technique for making photos more interesting and dynamic. In this image the main focus is on the buildings and there composition is in the upper two thirds. The other lower third is quite clear other than a change in colour.
In this image the main focus is on the young girl smelling the sunflower, the composition of this is in all three thirds . However vertically the girls eyes are in the the upper third of the image and her nose, mouth, chin and sunflower positioned in the middle thirds. This does leave the lower third a little bland and not as interesting.
In this final image the main focus is on the cat pitched on the log, this is positioned in the first and second third vertically to the left, the other third on the right is left slightly bland other than the colour of the trees. horizontally in the all three third there is something, upper there is the cats head, in the middle there is the body and on the lower layer there is the tail and the log its self.