Questions

Settled agriculture was first seen in China around 6000 BC. The crops grown at this time were rice and millet.

Beginning in about 618 BC with classical millet agriculture, China's development of farming over the course of its history has played a key role in supporting the growth of what is now the largest population in the world.

3 May

Radio waves have much longer wavelengths and lower frequencies than do visible light waves. In contrast, X-rays have much shorter wavelengths and higher frequencies. 

Ultraviolet Light (UV). part of the electromagnetic spectrum that consists of waves with frequencies higher than those of visible light and lower than those of x-rays.

Deep sea animals cannot produce food as there is no light. They have to depend upon the fall out of organic debirs raining down on them from surface layers. Hence they are detritivores.

Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms activities.

Photosynthesis can be represented using a chemical equation.

The overall balanced equation is

              $$\begin{gathered} 6CO2 + 6H2O →Sunlight C6H12O6 + 6O2 \\ Source of Carbon & Oxygen + \\ Source of Electrons & Hydrogen + \\ Energy that drives Photosynthesis ----> \\ Sugar + Gas produced by splitting water. \end{gathered}$$

Where 

CO2 = carbon dioxide 

H2O = water

C6H12O6 = glucose 

O2 = oxygen.

The flow of thermal energy due to differences in their temperatures is called Heat.