Assumption - hope this helped took the test and got 100
It gains purchasing power. Less money in circulation = more value.
Because most people really don't want or need to see what's in there.
If you want to, open the door during the cycle. It won't harm anything.
If you're curious to see a dishwasher in action, some appliance showrooms have a display model, where the spray parts and the racks are in an entirely transparent box. They're to show how powerfully and completely the stuff inside will get cleaned, but you can also see how the dishwasher is intended to work, by filling with just a couple of inches of water, and then recirculating it for the duration of the cycle, to loosen the stuff on the dishes.
