COCA-Cola Amatil executives and lobbyists for the food and beverage industry will face questions today on their "level of responsibility" for pollution created by plastic containers, at a Senate inquiry on marine pollution.   Coca-Cola and the Australian Food and Grocery Council both oppose a container deposit scheme.   Environment and Communications Committee chair, Senator Anne Urquhart said the committee had heard from witnesses who were frustrated the beverage industry had "actively stifled container deposit scheme development" despite such schemes reducing litter "by a factor of three".   "The committee has heard that the majority of coastal and marine plastic is generated locally and beverage containers make up 40% of the litter, so there are some very legitimate questions to ask about the level of responsibility that industry should take for the rubbish it generates," she said.   AFGC opposes such a scheme because it would cost industry or government possibly billions. CCA has argued it has other initiatives to deal with litter.