填空题 A industrially polluted soils
B rock and soil chemistry
C naturally polluted soils
D the pathways of metals into the food chain
E the element of iodine
F the persistence of heavy metals

填空题 Some serious diseases is connected with deficiency of ______.

填空题 It is extremely necessary to study the long-term effects caused by living on ______.

填空题 Geologists are indispensable in the research project on geology and health due to their knowledge on ______.

填空题 Industrially contaminated sites usually require a thorough clean-up due to ______.