McDonald's, Greggs, KFC and Subway are today named as the most littered brands in England as Keep Britain Tidy called on fast-food companies to do more to tackle customers who drop their wrappers and drinks cartons (盒子) in the streets. Phil Barton, chief executive of Keep Britain Tidy, (1) its new Dirty Pig campaign, said it was the first time it had investigated which (2) made up "littered England" and the same names appeared again and again. "We (3) litterers for dropping this fast food litter (4) the first place but also believe the results have pertinent (相关的) messages for the fast food (5) . McDonald's, Greggs, KFC and Subway need to do more to (6) littering by their customers." He recognised efforts made by McDonald's, (7) placing litter bins and increasing litter patrols, but its litter remained "all too prevalent". All fast food chains should reduce (8) packaging, he added. Companies could also reduce prices (9) those who stayed to eat food on their premises, offer money-off vouchers (代金券) or other (10) for those who returned packaging and put more bins at (11) points in local streets, not just outside their premises. A (12) for McDonald's said:  "We do our best. Obviously we ask all our customers to dispose of litter responsibly." Trials of more extensive, all-day litter patrols were (13) in Manchester and Birmingham. KFC said it took its (14) for litter management "very seriously", and would introduce a programme to reduce packaging (15) many products. Subway said that it worked hard to (16) the impact of litter on communities, (17) it was "still down to the (18) customer to dispose of their litter responsibly". Greggs said it recognised the " continuing challenge for us all ", (19) having already taken measures to help (20) the issue.