As part of our homework over Easter, Mr R has asked us to collect 10 reversible and 10 irreversible changes.  Once these have been collected, post them onto the blog by adding a comment below.  Mr R will publish these on the last weekend of the holidays.  The 10 people who give an obscure answer (eg examples which nobody else have given – eg ‘Pointless’ answers) will each receive a team point.  Good luck!