You don't need drawings and jewels when you close it, but you need a drawing to upgrade buildings above 10, and there are many jewels (the higher the level, the more you need them).

Just need a famous city contract.

Let me introduce you to the skills of closing the city.

The resources outside the main city are 1 wood 1 stone 1 iron, and the rest are all farmland. There is a building in the city (it must be complete), 4~8 barracks are recommended by individuals, and the rest are private houses.

Divide all iron mines outside the city. Of course, other 1 is also possible. It is best to build a whole barracks in the city. Of course, this is impossible, so try to have barracks and buildings, such as warehouses, which are not necessary.

As far as I know, the rule of merging cities is: after determining the main city with a famous city contract, the main city can be merged five times, which means that five sub-cities can be merged. Once each city is merged, the government will be upgraded by one level, and the last level is 15. Every time the main city is merged into the city, the rest of the buildings have to be upgraded (the official upgrade is free), depending on the resources needed for the construction of the sub-city. In other words, the greater the construction cost of the sub-city, the more upgrade resources the main city gets, so the iron mine outside the sub-city is divided into barracks in the city. The cost of upgrading the main city is too high. Farmland outside the city and four barracks in the city are enough, not too many barracks, otherwise it will not be upgraded.