A. industrially polluted soils
B. rock and soil chemistry
C. naturally polluted soils
D. the pathways of metals into the food
E. the element of iodine
F. the persistence of heavy metals
Geologists are indispensable in the research project on geology and health due to their knowledge on______.

A. The lower the temperature, the higher the amount of methane emissions.
B. Living plants releas less methane than dried plants at the same temperature.
C. When exposed to sunlight, plants stop releasing methane.
D. The higher the temperature, the greater the amount of methane emissions.

A.watched
B.followed
C.understood
D.grasped