The sentences given below, when properly sequenced, form a coherent paragraph. Each sentence is labelled with a number. Decide on the most logical order and enter the sequence of numbers in the space provided. Only numbers are to be entered in the space provided for the answer, and no letters, characters, or spaces should be entered. For example, a response such as 3412 is valid and responses such as 3412. or 3 41 2 are invalid.

1. During the last 150 years or so, the world production of food has increased for two main reasons.
2. At the same time the development of various branches of science, and in particular medical science, has helped to eliminate or lessen the effects of many diseases, enabling more adults to reach old age.
3. New lands have been brought into use for farming for the first time, and new techniques have made it possible to obtain higher yields in existing farming areas.
4. The relentless growth of world population over the last 150 to 200 years was only possible because more and more food and other items of consumption became available.