[Grammar] Most everyday items contain carbon, usually as plastics – computers, medicines, cars,

[shibli.aftab]

"Most everyday items contain carbon, usually as plastics – computers, medicines, cars, clothes, buildings. Most of this carbon originates from petroleum or coal, fossil fuels buried underground for millions of years."

Can we rephrase above sentence as below?

"Most everyday items contain carbon, usually as plastics – computers, medicines, cars, clothes, buildings. Most of this carbon originates from petroleum or coal, fossil fuels that were buried underground for millions of years."

Thanks

 

[SoothingDave]

Yes.

 

[shibli.aftab]

Can we put "which have been" at the place of "that were" without changing the meaning?
Thanks

 

[emsr2d2]

Yes.

 

[Grumpy]

Yes.
Also, I would start your first sentence with "Many" to avoid two successive sentences beginning with "Most".