All weapons, tools and armor in the game are of two types — enchanted metachromasia. To fix first you need an anvil, it is possible not only to repair objects, but also to combine different sets of enchantments. The usual armor, weapons and tools can be repaired in the window of the craft (the creation of subjects).
Using the workbench or Windows inventory you can combine two damaged item, if they are made of the same material, so you can combine two damaged iron sword to get one less damaged. Because the bow can only be made of wood, it this rule does not apply. The status of the received object always depends on how much was damaged original, used for fix. Therefore, if you have no problems with resources, in particular threads, much easier to make a new bow. The usual fix tools in Minecraft not too meaningful. Enchanted is another story.
Unfortunately, in the crafting window it is impossible to repair enchanted items, because it destroys the beneficial properties. To keep enchantment, you need to use the anvil. To make an anvil, you need to fill in the upper horizontal on the workbench blocks of iron, lower the iron ingots and put in the Central cell of another iron ingot. Anvil allows you to repair items with materials from which they are made, respectively, the onion can be repaired using a stick or thread.
To repair items or combine their charms, you need expertise. Experience can, extracting minerals (coal, lapis lazuli, red stone, diamonds) or killing monsters and animals. Any procedure on the anvil will require a certain cost levels. For example, the usual fix enchanted bow with floss or sticks will take the character up to five levels. If you want to combine two enchanted bow with different enchantments, it can take up to forty levels.
On the anvil it is possible not only to repair the bow, but also give it a special name. Length of the name cannot exceed 30 characters. This procedure also takes some amount of experience, for ordinary objects it is less for enchanted - more.