Answer:
we can help them sharing some time with them. The solitude is a bad situation and a lot of people leave their grandparents alone. We also can make they happy also with small things or small actions.
The wheel, plow, and writing (a system which we call cuneiform) are examples of their achievements. The farmers in Sumer created levees to hold back the floods from their fields and cut canals to channel river water to the fields. The use of levees and canals is called irrigation, another Sumerian invention.
Maybe right depends on the subject but a major study shows that poor countries have higher birthrates but in first world countries there is less thats is why there is less babies being born in the 1st world countries because of the better health care and access to cleaner water and more food and economic growth and lesser corruption so the awnser would be economic growth or you can rephrase the words i used to make an awser that fits hopefully i helped
We say that a single study proves a theory because those who are smart enough can get it done quickly, and we say that a single study disproves a theory because that means it makes them feel smart when we disprove someone very intelligent but also it's to make sure if nothing was done wrong