Answer and explanation;
The use of coal has steadily increased from 1800 to 2004. Burning coal was the leading cause of global fossil carbon emissions. Petroleum use rose quickly after 1950.
Coal can be defined as a sedimentary rock that burns. It was formed by the decomposition of plant matter, and it is a complex substance that can be found in many forms.
Energy consumption patterns have changed over the history of our country as we developed new energy sources and as our uses of energy changed. Coal became dominant in the late 19th century before being overtaken by petroleum products in the middle of the last century, a time when natural gas usage also rose quickly.
Wavelength= speed / frequency
so.....3× 10^8 / 7.26×10^14
= .413× 10^(-6)
in scientific notation= 4.13×10^(-7)
in nanometer = 413 nm
look it up on Google I will give you the answer
The answer is D. They already knew about animals, plants and skin.