Fluorosis is caused due to the presence of excessive amount of ______________ in drinking water?

A. Decreases
B. Increases
C. Remain constant
D. May increase or decrease; depends on the chemical characteristics of polluted water

A. Acetylene
B. Petrol vapor
C. Hydrogen
D. Carbon monoxide

A. Ozone
B. Photochemical smog
C. Sulphur dioxide
D. All A., B. & C.

A. Turbidity
B. Color (Hazen)
C. Total solids
D. All A., B. & C.

A. Grey
B. Dark brown
C. Red
D. Black

A. Roentgen
B. Decibel
C. Hertz
D. None of these