The Precambrian era envelopes the major bulk of the history of the Earth, beginning from the creation of the planet approx 4.5 billion years ago and terminating with the origination of composite, multicelled forms of life approximately 4 billion years after.
The Precambrian refers to the earliest of the geologic ages that are signified by the distinct layers of sedimentary rock. The Earth was about more than six hundred million years old when life started. The planet had cooled down from its native molten state, creating a solid crust and oceans formed by water vapor in the atmosphere.
At about three billion years ago, the atmosphere of the Earth was virtually devoid of oxygen. At approximately 2.4 billion years ago, oxygen was discharged from the seas as a waste product of photosynthesis by cyanobacteria. The levels of the gas slowly raised, attaining about 1 percent around two billion years ago.
Approximately 800 million years ago, the levels of oxygen attained about 21 percent and started to breathe life into more composite species. The oxygen-rich ozone layer was also created, protecting the surface of the Earth from the harmful solar radiation.
<span>The point beneath the surface where rock breaks and an earthquake is produced is known as the focus.</span>
Answer:
Tbh they come from the Male sperm and the Female egg. Once the sperm fertilizes the egg then you have a baby! That's the short and simplified answer
Explanation:
Explanation:
we all want to improve air quality in our environments. especially in cities.., unfortunately, the $ you save from "going green," will now cause extra taxes,in the near future, which will defeat the purpose of saving $...from green sources adding another tax for your hard earned resources, example, when u buy a property with wooded areas, in rural towns of illinois, you are charged a green tax, plus higher property taxes to compensate electricity.
therefore, investment in clean energy shud b divided into yearly income per year..hense, people of higher income shud b taxed mor to the rich and people who can afford it. bluecollors are always taxed more than peps
that can actually afford it..
just my thought...
