They benefit fast-food chains,since the tax on takeaway is only 5.5% percent,while they penalize sit-down restaurants,whether humble bistros or haute cuisine,which pay19.6%.
They benefit fast-food chains,主句,since the tax on takeaway is only 5.5% ,原因状语从句。while they 到 19.6%,并列句,跟while前面的形成对比。whether humble 到 cuisine,让步状语从句,修饰前面的sit-down restaurants。which pay 19.6%,定语从句,同样修饰sit-down restaurants