Page 3 of our 'basic techniques' series of Muay Thai tutorials, dealing mostly with combos.
Note that these videos are not a substitute for proper instruction, but rather, that they should allow you to review what you have learned in class...
Jab-cross combo
Cross followed by a roundhouse
Blocking a jab-cross combination and countering
Block, kick,kick,cross,kick combo
Kick followed by a knee
Jab, cross, block, kick, block, knee