Wheel
Writing
Calendar
legal code and number system
Answer: Electronic mail
Explanation:
Electronic mail is the exchange of messages between people using electronic devices. Electronic mail predates and was also crucial to the establishment of the Internet.
Electronic mail (E-mail) started in 1965 as a way for the multiple users of a time-sharing mainframe computer to communicate and send amesages across to each other.
Answer:
much lower
Explanation:
the water was frozen
with that ice melting now the water levels are rising
Invasions by Barbarian tribes
Economic troubles and overreliance on slave labor
