26 Paragraph 6 ___________
A No evidence to indicate bad effects of naturally contaminated soil
B Potential hazards of human contaminated soils
C Research on channels of heavy metals getting into human food chain
D Geology and health problems
E Rocks-the ultimate source of soil pollution
F long-term health effects on children
27 Some serious diseases is connected with deficiency of _____________.
28 It is extremely necessary to study the long-term effects caused by living on ___________________.
29 Geologists are indispensable in the research project on geology and health due to their knowledge on ___________________.
30 Industrially contaminated sites usually require a thorough clean up due to ___________________.
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