plump * down
He plumped his bag down and kicked his shoes off.
plump oneself down +
She plumped herself down next to me and started asking me what had happened.
I poked about in my CD collection to see if I could find it.
pore over +
She pored over the report looking for mistakes.
power * down +
I powered down my computer and went for lunch.
power * off +
You mustn't power it off while it is updating.
power * up +
I powered up my laptop and started work.