You approach the technician and say 'What are you doing?' He replies:
'I am reinstalling this lightbulb. You see, quite often these special government-issue Mega$loth® lightbulbs stop working for no apparent reason, and have to be taken out of their sockets and put in again. After that, they go on for a while, and then the whole palaver has to be repeated.
'If you want to know more, why not go through the door on your left.'
After thanking the man for this useful piece of information, you decide to: