Which group of people had knowiedge of the moon and Venus: a 365 day calendar; a system of mathematics; and a number system?

Of all the world's ancient calendar systems, the Maya and other Mesoamerican systems are the most complex, intricate and accurate. Calculations of the congruence of the 260-day and the 365-day Maya cycles is almost exactly equal to the actual solar year in the tropics, with only a 19-minute margin of error.

Maya astronomer-priests looked to the heavens for guidance. They used observatories, shadow-casting devices, and observations of the horizon to trace the complex motions of the sun, the stars and planets in order to observe, calculate and record this information in their chronicles, or "codices". From these observations, the Maya developed calendars to keep track of celestial movements and the passage of time. The Maya also kept detailed records of the moon, although these do not seem to constitute a formal lunar calendar

Explanation:

american troops were forced to withdraw following deadly bombings.

explanation: