In this task, you are given an article. Your task is to summarize the article in a sentence.

[Q]: Nigel Farage is wondering why, as Jonathan Portes has been pointing out, the Office for National Statistics (ONS) figures for migration to the UK from other EU countries is so much lower than the number of National Insurance numbers allocated to EU nationals.
According to the most recent comparable statistics, migration to the UK from the rest of the EU was 257,000 in the year to September 2015, but during the same period, 655,000 EU nationals registered for National Insurance numbers (Ninos).
Mr Farage smells a rat: "They are pulling the wool over our eyes. Ninos are a simple and clear reflection of the real numbers of people in this country, as without them you can neither legally work, nor claim benefits."
Now the government has promised to tell us how many of the Ninos issued are still active - in other words, how many of the EU citizens who registered are currently paying UK tax or claiming benefits.
But are Ninos a good measure of immigration?
There is no question that the official immigration figures, based on a survey taken at ports and airports, are imprecise, with the ONS 95% confident that the immigration figure is within plus or minus 23,000 of the true figure.
More importantly, though, the ONS figures only aim to measure long-term migration. They use the UN's definition of a long-term migrant as someone who moves country for a year or more.
When it comes to National Insurance numbers, on the other hand, there is no minimum stay in the UK. Everyone who wants to work in the UK must have a National Insurance number, even if they're only working in the country for a few weeks.
What's more, Ninos are unique to an individual, so once you've received one, it's yours forever. This means that not all those who HMRC reveal to be "active" will necessarily belong to people who have been in the country continuously since their number was issued - they could have left and returned.
The ONS statistics also include people who are not planning to work or claim benefits, such as children or non-working partners. These people don't need a Nino when they arrive, but can apply for one in the future. This means someone registering for a Nino could have arrived at any time, not necessarily in the year or quarter in question.
It's not hard to see how the two sets of figures would be different. The question is, should they vary this much, or is there a problem with the way the ONS currently gathers its data? HMRC has said it will work with the ONS to help reconcile all available sources of statistics, including Ninos, to ensure the figures are as accurate as possible.
With this process rumbling on - and the latest immigration and Nino statistics due out on 26 May - this issue is sure to keep providing fuel for the EU debate, coming just a month before the referendum.
Reality Check verdict: There are good reasons why the two numbers would be different, but they are strikingly far apart, and next month's figures showing how many of the numbers are active should help reconcile the two.
READ MORE: The facts behind claims in the EU debate
[A]: Campaigners to leave the European Union have been badgering the government about the reliability of the official immigration statistics.


[Q]: Sadiq Khan said there was real concern among business leaders that companies could leave the City.
It comes as the mayor of Frankfurt told BBC London his city's "arms and our doors are open".
London-based financial technology firm Transferwise said it had been courted by several European countries already.
The company's chief executive Taavet Hinrikus said his company was being courted by Ireland and Switzerland among others.
A spokesman for Transferwise, which processes international currency payments, said moving away from London was "not something the firm was actively talking about".
The spokesman added that Transferwise had chosen to make its base in London and that the company "hoped it could make that work".
But he added that businesses needed greater certainty in order to operate successfully.
Mr Khan told BBC London there was genuine concern among leading figures in the City he had spoken to, including Bank of England governor Mark Carney and London Stock Exchange chief executive Xavier Rolet.
"There is a concern that if we don't have access to the single market, if we haven't got passporting of financial services, that could lead to businesses leaving London to go to those cities where there is access to the single market," he said.
The latest government figures estimate the FinTech industry - financial technology - generates about Â£20bn in annual revenue.
And Mr Khan said it was just one industry being targeted by other European centres.
"The mayor of Milan was here this week, I met with him, Why was he here? He wants to pinch our business. Who can blame him?
"The mayor of Paris and the deputy mayor have already said they're rolling out the red carpet to invite businesses to come to Paris. Why wouldn't they?"
Dublin-based investment group IDA Ireland is planning an advertising campaign in the autumn highlighting Ireland's tax regime, its proximity to London, and the shared language to businesses thinking about relocating.
Peter Feldmann has had a busy few days. Frankfurt's lord mayor has been celebrating the birth of his second daughter on Monday night.... and who knows perhaps a new lease of life for his city too.
He greets us in the grand surroundings of the Kaiser Hall in Frankfurt's equally grand City Hall and can barely contain his smiles.
Opportunity, he believes, has come knocking with the UK's decision to leave the EU.
"Our arms and our doors are open," he tells me when it comes to London businesses big and small that are looking to relocate.
At a business meeting the day after the Brexit vote, people cheered and clapped him saying: "here is the winner from Brexit".
In the coming weeks his team will fly to London to make their case. Frankfurt already has a video selling its wares and a team of English speakers taking calls from businesses.
Mr Khan told the BBC: "London is open: we're open for talent, we're open for business, we're open for investment. The government has got to help me do my job as mayor to make sure that we send that message out loud and clear around the country, around Europe and around the world.
"We've got competitors who want to pinch that business, we've got competitors who want businesses to go to their cities. We cannot allow that to happen."
Business and Energy Secretary Greg Clark said giving businesses the certainty they need to plan for the future is a "key priority".
"That's why we are working closely and collaboratively with businesses across all sectors to ensure that the UK remains the best place in the world to do business," he said.
A minute after the Brexit vote was announced Frankfurt launched a website and phone line in a bid to encourage businesses that want to remain in the single market to relocate there.
The mayor of Frankfurt, Peter Feldmann reiterated that invitation on Thursday, telling BBC London: "If you want to become rich, if you want to stay wealthy, you should have a [department] in Frankfurt.
"If you want to become isolated and see from a binocular perspective what is going on in the world, stay in London."
Meanwhile, German business development group Berlin Partner said earlier this week that at least 10 London start-up firms had made enquiries about moving to Berlin since the UK voted to leave the EU last month.
Berlin is attempting to woo London's FinTech industry and, like Frankfurt, has stepped up efforts to promote itself as a more affordable and creative alternative to other cities.
At London's FinTech conference earlier this week, Berlin Partner director Stefan Franzke said: "The most concrete enquiries are coming from London FinTechs. They are considering a move to Berlin so as not to lose access to the European single market."
Berlin's senator for economics, technology and research, Cornelia Yzer, has sent hundreds of letters to UK businesses and earlier this week travelled to London Fintech Week to lobby start-up founders.
She told BBC London: "We are an international community and that's why companies will find talents there they need. So welcome, and we'll bring all hurdles down, we'll offer programmes for relocation. So pick up the phone talk to me and my team and relocate to Berlin."
More than 100 companies have already been in touch with her team since the Brexit vote, she says, and in September they will open an office in London.
But Mark Boleat policy chairman at the City of London Corporation said he remained confident London would continue to be the world's leading financial centre.
"While some European cities might look to entice businesses and jobs to the continent, we have so many strengths which make us such an attractive place to do business," he said
"Highly skilled workers, excellent infrastructure and a stable regulatory system are but some of those, and crucially the capital is a place where people want to work and live."
Asked whether London had been ill prepared for the Brexit result, Mr Khan said that was now important was that London now dealt "with the hand that we've been given".
Mr Khan said it was "really important that we explain to the government it's in the country's interest for them to listen to us."
"Uncertainty isn't helping."
[A]: The mayor of London has warned of the growing threat of foreign cities trying to steal business from the capital, one month on from the EU referendum.


[Q]: Finola Cash, 32, was out buying crack cocaine when her son Ricky's bath seat fell into water in their hotel bedsit in Edgware, north London, in August.
Cash had been visited by social workers on multiple occasions, including on the day Ricky died, the Old Bailey heard.
The judge said Cash was "grossly negligent".
The baby, who was subject to a child protection plan by Harrow Social Services, died in September 2014 - a month after he was found - in a children's hospice after suffering brain damage.
Judge Charles Wide said: "You were grossly negligent. This was not the result of momentary inattention, this was the culmination of the continual failure to care for him.
He added: "You were more concerned with receiving your consignment of drugs than looking after your child."
Doctors found the 11-month-old had crack cocaine in his bloodstream, which was either the result of passive smoking or contamination from a surface or a finger.
He was also suffering a severe nappy rash caused by neglecting to change soiled nappies.
Cash pleaded guilty to manslaughter and was sentenced to six years, of which Judge Wide said she is expected to serve half on licence.
Cash, who is from the travelling community, was known to social services because of her history of drug abuse and domestic violence.
She had been moved into the hotel so social services could supervise the family, the prosecution said.
On the morning of Ricky's death on 23 August, a social worker made an unannounced visit to Cash and noted that she had no concerns, the court heard.
Tests on her blood and hair revealed she had taken crack cocaine in the 12 hours before Ricky had drowned and had been a user of heroin and methadone for the previous nine months.
Sarah Plaschkes QC, prosecuting, said Harrow Social Services became "increasingly concerned" about Cash who had already been evicted from two other hotels for disruptive behaviour before she arrived at the Madonna Halley Hotel, in Whitchurch Lane, in August 2014.
Social workers suspected Cash may have been taking drugs after reports from from neighbours, but Cash failed to turn up for drug testing.
A statement from the Met Police said Harrow Council had launched a multi-agency serious case review commissioned by Harrow Local Safeguarding Board.
[A]:
A mother whose 11-month-old son died after sustaining injuries while she was out meeting her drug dealer has been jailed for six years.


