{"answers": "A", "options": ["f : wow , i did n't expect that the population of london would not be in the top ten !", "f : london had a population of 20 million in 1950 , but i did n't expect that the population of london would not be in the top ten !", "f : by 2000 , 36 million people will live in mexico , and its population will not be in the top ten !", "f : new york ranked 11th in 1950 , but its population did n't even reach the top ten !"], "article": "f : in britain , we are often told that people are leaving the big cities to live in the countryside , but is this the same worldwide ? m : not at all . if you look at the biggest cities in one thousand nine hundred and fifty , 7 out of the top 10 were in the developed countries . but by the year two thousand , the developing countries will have 8 out of top 10. new york , which in one thousand nine hundred and fifty , was number one with a population of around 12,000,000 will only be the sixth the largest city in the world , but with an extra 2 million . f : and london ? m : london , which was number 2 , wo n't even be in the top ten , its population in one thousand nine hundred and fifty , by the way , was about 10,000,000 . f : and why is this happening ? why are people moving to the big cities from the country in the developing countries ? m : the reasons are various , but many are moving to look for work and the problems caused by this are enormous . it said the 26,000,000 people will be living in mexico city by the year two thousand , with sao paulo in brazil , not far behind .", "id": "train_660"}