Transform
Into. The chemicals are later on transformed into a mixture signifying a risk to human health.
Level.
At.
Waste
On. I wasted all my time on video games and had to cram and burn the midnight oil
Expand
On. You should expand on new areas of interests such as Sustainability and Green Economics
Employ (verb)
On. Oddly, he was employed on a job with very resembling working conditions.