Please choose the correct ending to complete the given sentence: Health: [header] How to reduce radon [title] Take radon-reduction training courses. [step] Without the right equipment and techniques, you could actually increase the levels of radon in your home! If you decide not to use a certified contractor to reduce radon, it's essential that you contact your state radon office to find training courses in your area. Enroll in and attend these training classes to learn how to properly reduce radon levels.

Ending1: [substeps] For instance, you'll learn how to properly test for radon. You may also be taught how air pressure affects ventilation and how radon moves through water. Ending2: Your area will have some information on " local " radon manufacturer training programs. [substeps] It's best to talk to a supervisory/certified contractor before taking any oiling classes. Ending3: [substeps] Also pay attention to lighting (sunlight will slow down radon levels) and ventilation. Water soluble radon can fall down your drain. Ending4: [substeps] Many websites offer basic scas training courses but others will provide recommendations on how to make water consumption safer. Ask your local environmental authority for a list of certified contractor qualified to train.

Answer format: ending1/ending2/ending3/ending4