In this task, you're given an article and an answer. Your task is to generate the question for the answer based on the given article.

Let me give you an example: Article: There are a lot of public libraries in Britain. These libraries have more than one hundred and fifteen million books, not including those libraries of public schools. Public libraries not only lend books, music records but also help children, patients in hospitals and others to get special play readings, film shows and so on. The first public libraries were founded in about the year 1850. Today's public libraries usually have a reading-room, a lending room and a reference room. The greatest and most famous library in Britain is that of the British Library in London. It was founded in 1973 and has over 10, 000, 000 books. It has nearly every magazine, newspaper and book published in Britain and other parts across the world.
Answer: 10,000,000 or less.
The answer to this example can be: How many books are there in the British Library?
Here is why: In the Article, 10,000,000 is mentioned for the number of books available in the British Library, so this is a good question.

OK. solve this:
Article: Every year, Americans send millions of tons of food to the landfill . What if you could use all of those rotten vegetables to heat your home? That's happening in one unlikely laboratory: the Newtown Creek Wastewater Treatment Plan in Brooklyn The plant's longtime manager, Jimmy Pynn, shows off the plant's crown jewels: eight huge, shiny, oval-shaped steel tanks known as digester eggs. Each one contains millions of gallons of black material that's roughly pea soup. Pynn calls it "black gold". "The digesters like to be fed like us: three times a day," he says. "They like to be kept warm, 98 degrees. And that's what we have these guys for: to make methane ,which can be used to heat homes or make electricity." Right now, what these bacteria are digesting is mostly sewage mud. But they are being introduced to a new diet food scraps. The hope is that this plant will soon take in hundreds of tons of organic waste from houses and apartments. "Cardboard packaging, rotten tomatoes, fats, oils, old diary products--those are all great food-stuff for a digester," says Paul Sellew. "My micro-organisms love that. That's their five-course meal." "Everything in New York City is like big scale when you're talking about quantities of waste," says Samantha MacBride. "Right now, it's all in its infancy. When you're in an apartment building, to separate out food scraps, it requires a lot of effort and attention," says MacBride. "It doesn't have to have unpleasant smell or be inconvenient. But it takes extra work. It's the first, what I will call the baby step," says Paul Sellew. "Because ultimately in New York City, just the restaurants alone, you're talking well over a million tons a year," he says. This new industry is trying to build more plants and digesters to handle all of that waste, says Sellew. The costliest part may be finding good locations in or around the nation's biggest cities. As for the trillions of bacteria? They'll work for free--- as long as you feed them.
Answer: To make crown jewels.
Answer:
What role are the digester eggs expected to play?