Which of the following are true statements?

		You are not allowed to charge money for Linux or open source software.
		Some companies make the source code used to create to their software available, but their license says you must still pay to use the software and you are not allowed to give away copies.
		Some software is made available without requiring that you pay any money, but the license does not allow you to modify the software or provide you with the source code that was used to create the software.
		If you can find a place on the Internet to download a particular piece of software, it must mean that it is free.