Answer:
2.1 children per family
Explanation:
When the total fertility rate is at replacement (2.1 children per family), the two children born essentially replace the parents when they die. The replacement level TFR is 2.1, not 2.0, since not all females survive to their childbearing years.
gunpowder
The invention of gunpowder.
This period is also known as the medieval period and is known for the various discoveries and inventions made during this age.
Investment (and NO stock has a guaranteed return).