Tell us what this is and maybe someone can answer
No, you should not be worried. It is fine.
Does the friend has the history of stealing. If he does then you should be worried, but if he does not you should not be worried. But to be safe, you can keep you stuff on safe place to avoid excuses.
Yes, you should be worried if it was not caused by mosquitoes or falliing.
should i be worried about this bump at the corner of my right ears?
You should never be 'worried' about girls. They are not dangerous, unless you lack self-control.
you should be some what worried because that could mean that you are not socializing him properly.
Depends if you want to be pregnant. If not you should be worried...
The most dangerous type of radiation is Nuclear radiation which is the one that should be most worried about.
At 5'7, you should most certainly be worried.
Yes you should be worried. You should get the microwave tested for radiation leakage before you use it again.
No. It depends. If this is your cousin's first time going skydiving, you should be worried. If your cousin has many dives under his/her belt, then you shouldn't be too worried.
Yes.