suspended impurities
dissolved impurities
both suspended and dissolved impuri¬ties
none of the above
contains pathogenic bacteria
consists of undesirable substances rendering it unfit for drinking and domestic use
is safe and suitable for drinking and domestic use
is contaminated
dysentery
cholera
typhoid
maleria
carbon dioxide
oxygen
hydrogen
nitrogen
0.1 ppm
0.01 ppm
0.001 ppm
0.0001 ppm