two-particle phrasal verbs

Hello
I am studing phrasal verbs with 2 particles and sometimes is difficult for me to understand their meaning. Another problem I usually have on phrasals exams is that I have a sentence and I have to complete it with the right phrasal verb and although I studied it, I don't realise that I have to write it there. Do you understand what I mean? I don't realise from the context.

well.. I would like to know the meaning of:

*fool around with something (I looked it up but I still don't understand)
*keep up with (I know the meaning of it but I need an example) =)
*pull out of (I don't know the meaning.)

Muchas Gracias (Thank you!!)

[Tdol]

Fool around with- It can mean toplay/mess about, but it can also mean to have a sexual relationship outside a marriage
He walks so fast that I can't keep up with him.
Pull out of- withdraw- He pulled out of the race because of an injury.