How are Leeches helpful to humans?

(I'm doing a paragraph on this so I need help ASAP!)

They are helpful because they produce an anticoagulant and literally suck blood from the surface of skin, they are often used to revive delicate veins and improve blood flow following a tissue reattachment procedure.

Explanation:

the answer is a) the proclamation of 1763.

2686-2181 bce-- "egyptian civilization developed along the nile river in large part because the river’s annual flooding ensured reliable, rich soil for growing crops."

1069-664 bce-- "ancient egyptians developed wide-reaching trade networks along the nile, in the red sea, and in the near east."