The aztec city of tenochtitlan was located near the site of which present day city

It was located near the present day city of Mexico City. It formed a confederacy with Texcoco and Tlacopán and was the Aztec capital by the late 15th century. Originally located on two small islands in Lake Texcoco, it gradually spread through the construction of artificial islands to cover more than 5 square miles. Hope this helped :))

The answer is:

The major industrial cities became overcrowded as workers from rural areas moved there.

and

Because of the steady increase in food production, the population nearly doubled between 1800 and 1850.