4. match the item in column 1 with the description in column 2.. . potential matches: . 1 : world population 1960. 2 : world population today. 3 : black death pandemic death toll worldwide. 4 : united nation's world population estimate for year 2050. answer. : 3 billion people. : 6 billion people. : 75 million people. : 10 billion people

The correct matches are:

World population 1960 - 3 billion people
World population today - 6 billion people
Black death pandemic death toll worldwide - 75 million people
United Nation's world population estimate for the year 2050 - 10 billion people

1960 is a year in the middle of the ''baby boom'', where the world population started to grow drastically, and the time needed for getting another billion on the total world population shortened significantly.
The today's world population is little over 7 billion people, though it might be close to 8 billion considering that there's a lot of unregistered population in the ''third world countries''.
The Black death is one of the biggest factors that the population in Europe stagnated instead of becoming larger, it killed around 75% of the population which totally changed the demographic picture of the continent.
The estimates of the UN about the world population growth, taking all factors into consideration, is that the world will slowly move closer to the number of 10 billion people, and the most responsible for this will be the African ever-growing population.