something that you succeed in doing after hard work
It is a great accomplishment to have graduated first in your class.

someone whose job requires skill with their hands
There is a big difference between items made by an artisan and those made by a machine.

an organized society where technology and culture are highly developed
Our civilization has evolved over many years.

words that are written or cut in something
She asks for an inscription on the ring.

an enemy; a person or group of people who attack ot hurt other people
They put heavy objects behind the gate to reinforce it from the invaders.

the act or process of supplying lands with water using pipes or other artificial methods
The ancient Egyptians had developed an irrigation system using water from the Nile river.

the total number of people who live in a particular area, such as a city or country
My home town has a population of about 60,000 people.

특수화하다, 전문화하다
In your letter, specialize who you're writing to.