Second part of essay Secondly, the food became more available than one hundred years ago. Success was reached in cultivation fruits and sereals. It was received resistant seed breeds which be able to grow in severe conditions. Also developing of filtration water from salts and heavy metal ions did water more cheap in dry regions. One of the most important invention in water filtration, I suppose, is ion exchange resins. Thanks to the resins it may to receive good quality drink water. In conclusion, this phenomenon was caused by inventions and discoveries of scientists. If we compare the quantity of scientific discoveries in the last hundred years and from 1000 to 1900 we note that these quantities will be equal or slightly differ