Instagram is my favourite social rating/networking site.
networking
Being a private detective can/must be a very interesting job.
must
My mom paid for he shoes with her credit account/card.
card
Paul must/can be on holiday- I haven't seen him for a few days.
must
The woman seemed nice and friendly, but she was actually a scam/fraudster.
fraudster
Amy's got some money so she's going a shopping/phishing spree.
shopping
Those mustn't/can't be Philip's shoes because they are too small!
can't
Don't shred/log on those documents because I need them!
shred