Acknowledgements

Course image Tristyan Lebrun [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] in Flickr made available under Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Licence.

Don't miss out

If reading this text has inspired you to learn more, you may be interested in joining the millions of people who discover our free learning resources and qualifications by visiting The Open University – www.open.edu/ openlearn/ free-courses.