- Electricity,whichcannotbeseenortouched,isindispensabletohumanlife.Withthecontinuousimprovementofpeople'squalityoflife,moreelectricalapplianceshaveenteredthousandsofhouseholds,butelectricityisadangerousthing.Ifwetouchitcarelessly,itwillinjureusagain.Al...
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