Are you cleaning the things around your house frequently enough? Test your knowledge below. And remember, these are generalities. If you live with pets, kids or other especially messy folks, you’ll probably want to intensify your cleaning game. Same goes if you have immunocompromised people living with you or visiting.

1. How often should you clean the microwave?

a) After each use

b) Once a week

c) Once a month

2. The oven?

a) Once a week

b) Once a month

c) Once a year

3. The dishwasher?

a) Once a month

b) Once a year

c) Never

4. The washing machine?

a) Once a month

b) Once a year

c) Never

1. b) You should wipe down the inside of your microwave weekly, says Whiteley, “not because of the microbiological danger, but because of the smell.” Unless you always cover the foods you heat up, some of them will end up on the appliance, and they’ll continue to cook every time you turn it on, leading to unappetizing aromas. If you’ve neglected your microwave to the point that its interior looks like a tie-dye T-shirt, Hensley has some advice: Put some water in a dish and microwave it on full power for three minutes, then leave the door closed for five more minutes. The resulting steam will loosen the residue, making it easier to clean off.

2. c) The average family should clean their oven at least once a year, possibly twice a year, says Hensley. (If you cook every single meal in the oven, you might want to up it to four to five times.) Regularly cleaning the oven prevents smells and reduces fire risk.

3. a) You might assume that, because this device cleans other items, it is always clean. But you’d be wrong. If you’re using your dishwasher regularly, you should at least check monthly whether old food and grime has collected in its crevices.

Sarah Vance recommends running a paper towel along the inside of the rim to see if anything has built up, though you may not like what you uncover: She says she was “shocked, appalled and disgusted” by what she found. Now, she just runs the machine once a month without anything in it to keep it pristin

4. a) It’s especially important to clean your washer once a month if you have a front-loading machine, says Michael Mattingly, executive director of product management for clothes care at GE Appliances. He also recommends leaving the door and detergent dispenser open after each cycle to allow them to dry.

He suggests checking the rubber seal on the door for buildup, which you can wipe out with a rag, especially if you have long hair or pets. You will also want to remove the dispenser drawer and clean it with hot water in the sink.