Every day McDonald's serves 69m customers, more than the population of Britain or France.
The company has what is estimated to be the most valuable fast-food brand in the world, cherished as a cheap dining option for families.
But do consumers perceive McDonald's as a socially or environmentally responsible company?
If they do not, it is in spite of the best efforts of Bob Langert.
In 1988, he took a temporary assignment managing a furore over polystyrene "clamshells" in which the company's burgers were served,
and which were being damned for their contribution to America's litter problem.
That turned into a 25-year career (he has since left the firm) dealing with the chain's various negative external effects.
It was a Herculean task, akin to being fashion consultant to Steve Bannon.
Apart from litter, he had to deal with animal welfare, environmental destruction, obesity and workers' rights.
When he began, the company's mascot was being dubbed "Ronald McToxic" because of the clamshell problem.
开始这份工作时，受汉堡盒问题影响，公司的吉祥物被称为“Ronald McToxic” 。
But he had more success than outsiders might think.
His book "The Battle to Do Good: Inside McDonald's Sustainability Journey"
他的书《The Battle to Do Good: Inside McDonald's Sustainability Journey》
is a must-read even for those who are cynical about the business of corporate social responsibility.
At times, the fast-food chain did not help itself. In the 1990s, it sued two Greenpeace activists for producing leaflets about its practices.
有时，这家快餐连锁店心不由己 。在20世纪90年代，该公司起诉了两名发传单的绿色和平组织积极分子 。
The ensuing "McLibel" trial gave the claims worldwide publicity and was described as the world's biggest corporate-PR disaster.
Mr Langert tried to reduce the damage. The company consulted panels of independent experts and engaged with campaigning groups.
兰杰特试图减少伤害 。该公司咨询了独立专家小组并和活动组织合作 。
On occasion it aimed to keep one step ahead of the activists—McDonald's took action even when there was little sign of public concern.
Shaving one inch off the napkins saved 3m lbs of paper annually, for example, but few consumers noticed.
Environmentalists did attack the firm for its impact on the Amazon rainforest,
saying trees were being cut down to make room for cattle pasture or the expansion of soy farming for cattle feed.
In 1989 the company announced that it "never has and never will buy beef from recently deforested rainforests"
and it has also worked to limit the expansion of soy farming in the region.
The rise of veganism amid doubts about the health effects of eating meat have given McDonald's new worries.
This could mean the closure of thousands of small businesses which serve the community.
Stress is widely perceived as contributing to coronary heart disease.
3.Herculean task 艰巨的任务
This herculean task was ultimately completed, but with discouraging slowness.
The company could be sued for damages.