Answer:
Currently the biogenic theory is the leading explanation for the formation of fossil fuels and it’s believed that the petroleum we most commonly use took anywhere from 1 million to 1 billion years to form and represents a wide spectrum of useful petroleum and natural gas products including methane, propane, butane, hexane, octane and others
Explanation:
Reference: www.sclubricants.com/fossil-fuels-oil/
Answer:
Some organs are both a source and sink. Leaves are sinks when growing and sources when photosynthesizing. Rhizomes are sinks when growing but become sources in the spring when they provide energy for new growth.
I think observation and measurable.
