Answer: The 600's
Explanation: Muhammad received revelation from the angel Gabriel, in Islam known as Jibril, the event marking the beginnings of Islam, and the revelation given to Muhammad, later to be formed and written in the Holy Book of Islam - Quran. Archangel pointed to verses, and ordered him to recite them, which will be recorded in Quran later. According to tradition, this event occurred in 610 AD, in a cave under the name Hira, located on the mountain Jabal an-Nour, near Mecca.
Answer:
The advantages is that you can study and form an idea of our past.
The disadvantage is, it all happened in the past, so you need to depend upon guessing too much to form your conclusions.
Explanation:
Prince Henry or alps know as Henry the navigator :) let me know if this helped