What does the squeaky wheel gets the oil mean?

This saying means that loud and obnoxious people tend to be heard and heeded.

If you don't complain about something you aren't happy with and that you actually need, no one is going to do anything to help you solve your problem, so you have to keep on bugging people until the...

The person (or thing) most in need of help (or service) gets the help. Or... you fix the thing that's broken, by paying more attention to it than the things.

It means that if you are loud and annoying enough, people will do what you want to get you to shut up.

Oil and petrol were obtain as the fossilized products of plants which lived millions of years ago on earth before the human race came into being.The land plants turned to oil and the aquatic plants...