Answer:
"it was once part of the organisms from which the fossil fuels formed"
Protein. im absolutely certain
Answer:
A.
Explanation:
cool . . this that correct.
By the late 1830s, botanist Matthias Schleiden and zoologist Theodor Schwann were studying tissues and proposed the unified cell theory. The unified cell theory states that: all living things are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells.