Oil and Plants
Light (electromagnetic radiation) forms a continuous spectrum there are no two main types.
The two main sources in water vapor are farming and manufacturing
The two main sources of air pollution are the toxins released from factories and automobiles.
No, the main sources of the Nile are the White Nile and he Blue Nile
The Blue Nile and the White Nile are the two main sources of the Nile River.
The two main sources of light energy are natural light from the sun and artificial light from sources like light bulbs and lamps. Both sources produce electromagnetic radiation that our eyes perceive as light.
Carbohydrate,fat
The Romans obtained their food by either growing it or by importing it. Egypt and Sicily were two of the main sources for Roman food.The Romans obtained their food by either growing it or by importing it. Egypt and Sicily were two of the main sources for Roman food.The Romans obtained their food by either growing it or by importing it. Egypt and Sicily were two of the main sources for Roman food.The Romans obtained their food by either growing it or by importing it. Egypt and Sicily were two of the main sources for Roman food.The Romans obtained their food by either growing it or by importing it. Egypt and Sicily were two of the main sources for Roman food.The Romans obtained their food by either growing it or by importing it. Egypt and Sicily were two of the main sources for Roman food.The Romans obtained their food by either growing it or by importing it. Egypt and Sicily were two of the main sources for Roman food.The Romans obtained their food by either growing it or by importing it. Egypt and Sicily were two of the main sources for Roman food.The Romans obtained their food by either growing it or by importing it. Egypt and Sicily were two of the main sources for Roman food.
Tigris and Euphrates
solar and wind
Rice and noodles.
Mutation and sexual recombination.