If a city gets bigger they need someone to lay down rules and laws and guide them, or else the city would enter chaos.
To keep law and order within the community. To make rules and to make people follow the rules. Also if there is a government then there is Justice within the people.
yes
usually
a large supply of slaves
Puppies have baby teeth like humans. As they grow they need larger teeth so he/she will grow permanent teeth soon.
Yes. But it means you would have to bike a lot. Thigh muscles grow larger with time, so you need patience.
It grew long before the 20th century. Agriculture gave man the means to establish towns that turned into cities because they didn't need to follow herds of animals to eat. With cities/towns came government, art, religion, and other needs of civilization.
There are many reasons why an organization may need to recruit. An organization may need to recruit in order to spread the word and grow larger for example.
Oysters and mussels do not shed their shells. They are bivalve molluscs and their shells grow larger with age.
Most shrubs with large leaves grow in shade and need larger leaves to gather thelight required to do their job.
You may need to purchase it through the internet. I would expect that there are some stores in the larger cities that might carry a couple of them in their stock.
Towns start to grow where mines are because the miners need a close place to live.