3. naturally occurring
4. fossilized plants or air bubbles ( probably the plants tho)
5. increased
6. the green house effect occurs naturally, it is being polluted both naturally and unnaturally, the unnatural pollution is contaminating our 'greenhouse" and that is horrible.<span />
Answer:
(1)Human cheek cells have a lining of flat and polygonal cells with irregular boundaries,which are arranged edge to edge.As a result,they seem to form a delicate sheet or lining of cells.
(2)They do not have cell wall,plastids and big vacuoles.
