Thats different for every cube (of difference not just the same type of 3x3x3) usaully gears and usually screws but if you want to know the most specific answer to your question go to your local buck or two and get one and open it up usaully usually3x3x3 have a cross like item *core holding only the centers (6) and screws and possibly springs to hold them on.
Simplified answer to the one above:
on a 3x3, a core, springs and/or screws holding the 6 center pieces.
No, oils are harmful for the plastic and make the cube feel squishy and slimy, use a sillicone based lube to lube your cube
play with it for a long time
Rubiks Cube
yes. it is safe to make ice in plastic trays.
cross 2 sides then then do it again
Lots of components make them work on the inside. The outside is made from strong plastic and the buttons are also make from plastic.
A lot of plastic is made from oil. You can make it from alcohol.
Plastic is made form oil. Oil contains many different polymers and monomers. Scientists combine these qualities to make plastic. Color is then added or extracted to make the plastic the desired hue.
Yes, if its made out of plastic.
Parkesine is one of the aerliest plastics. This plastic was made by Alexander Parkes, the first man to make plastic.
yes you can make plastic out of milk and vinegar
Try doing some brain teasers or games that make you think. Sodoku, Rubiks cube, and crosswords are always good. It doesn't help if you give up though; if you don't get it try again or ask someone to explain it to you. You should improve everytime you do one.