Based on the population pyramid above, which of the following will pose the greatest demographic challengeto China beginning in 2029?

Plz asap can someone find the answer or the mark scheme or anything plzzz you : ) ‘it's perfectly understandable that hundreds of millions of people around the world live close to volcanoes’ use evidence to support this statement. (6 marks)

Quiero una redaccion de yo soy medico y que tenga 10 lineas

All of the following occurred due to the invention of the railroad except