1. In 1900 the world population was 1.65 billion, now it's about 7.6 billion. In 2050 it is predicted to reach 9.7 billion.

Fragment w tekście: "During the twentieth century, the population of the world grew from 1.65 billion to 6 billion. Today it is 7.6 billion and by 2050 it is predicted to reach 9.7 billion." - W czasie XX wieku światowa populacja wzrosła z 1,65 miliarda do 6 miliardów. Obecnie wynosi 7,6 miliarda i do 2050 roku przewiduje się wzrost do 9.7 miliarda.

2. The biggest change in that more people live in cities than in countryside.

Fragment w tekście: "For the first time in history, more people live in cities than in the countryside." - Po raz pierwszy w historii więcej ludzi mieszka w miastach niż na wsi.

3. Megacities are cities that have more than 10 million inhabitants.

Fragment w tekście: "Across the globe there are 31 megacities - cities with more than 10 million inhabitants (...)" - Na świecie istnieje 31 megamiast - miast liczących ponad 10 milionów mieszkańców (...).