What happened to cities during the early middle ages?

The Middle Ages, or medieval time, is generally believed to have started with the fall of the Roman Empire in 476 and to have lasted about 1,000 years until about 1450. The beginning of the Middle Ages is called the Dark Ages because the great civilizations of Rome and Greece had been conquered.

Explanation:

i'm guessing this is from edg enuity so the answers would be, from top to bottom,

theodor schwann

matthias schleiden

robert hooke

rudolph virchow

anton van leeuwenhoek