One effect that plentiful harvests had on ancient civilizations of the mainland's river valleys was to help have larger populations and the need to have materials to survive.
Answer:
topography
temperature
distance from sea
altitude
latitude
slope of land
quality of soil
Explanation:
please mark me brainliest
Abiotic and biotic are the two important elements in an ecosystem
1. Density Differentiation is responsible for the distinct layers of the Earth. Denser materials (Iron, Nickel, and other elements) sunk deeper and formed the core while less dense materials(aluminum, calcium, oxygen, silicon, etc.) formed the crust and mantle.
2. The debris which were orbiting the Earth from an impact accreted together to form the Moon.
3. Volcanic Eruptions which spewed large amounts of gasses (carbon dioxide, nitrogen, and other gasses) were attributed for the creation of the first atmosphere here on Earth. This process is also known as Volcanic Outgassing.
4. All elements which are heavier than Iron (Fe) are formed from Supernova explosions.
5. The process involved in the formation of planets and the moon from materials in the solar nebula and debris is called Accretion.
I would say A, weather.
I hope this helps! :)