Parallelism

Parallel
Mary likes hiking, swimming, and bicycling.
OR
Mary likes to hike, to swim, and to ride a bicycle.
OR
Mary likes to hike, swim, and ride a bicycle.
OR
The coach told the players that they should get a lot of sleep, that they should not eat too much, and that they should do some warm-up exercises before the game.
OR
The coach told the players that they should get a lot of sleep, not eat too much, and do some warm-up exercises before the game.

Not Parallel:
The teacher said that he was a poor student because he waited until the last minute to study for the exam, completed his lab problems in a careless manner, and his motivation was low.
Parallel:
The teacher said that he was a poor student because he waited until the last minute to study for the exam, completed his lab problems in a careless manner, and lacked motivation.