I would like to know how the following controls works aswell how would you test to see if they do actualy work?

if i was to write it would take me all night. read your books! some are easy anyway.. gas tap turns gas on/off(open and close valve flame should go out) saftey cut off cuts gas off wen lid is closed (turn cooker on and close lid gas should shut off) get your head in your books if ur sitting it coz its hard to p.