Passage: Biopreparat was a system of 18, nominally civilian, research laboratories and centers scattered chiefly around European Russia, in which a small army of scientists and technicians developed biological weapons such as anthrax, Ebola, Marburg virus, plague, Q fever, Junin virus, glanders, and smallpox. It was the largest producer of weaponized anthrax in the Soviet Union and was a leader in the development of new bioweapons technologies.

Question: How many systems were there in Biopreparat?
18