you can give it to your teammates to make synthetic items! When you rest in the inn, you will be prompted to enter the teammate gift system! One is Mengxi Miscellany, Synthesis of gourmet recipes:

Lei Yuange (hidden weapons)

Mengxi Miscellany 75 pages+rusty farm tools = plum blossom mark

Mengxi Miscellany 76 pages+sewing needle = silver needle

Mengxi Miscellany 88 pages+rusty nail = piercing nail

Mengxi Miscellany 114 pages+bamboo cage = poisonous hive

Mengxi Miscellany 127 pages+gunpowder = thunder and fire beads.

Mengxi Miscellany 152 pages+coarse hemp rope = catapult

Mengxi Miscellany 23 pages+porcelain = Zhen Tianlei

Xing Xuan (food)

Gourmet party 17 pages+eggs = tea eggs

Gourmet party 18 pages+pork = cured meat (pork is found in many places)

Gourmet party.

Gourmet party 82 pages+hawthorn = candied haws

Gourmet party 85 pages+carp = carp soup

Gourmet party 97 pages+chestnut noodles = palace snacks

Gourmet party 99 pages+glutinous rice cake

Gourmet party 17 pages+apples = applesauce

Gourmet party 129 pages+persimmons.