16 .Deficiency of which one of the following cause knock knee, bow legs and pigeon chest in children-
17 .Cobalt - 60 is commonly used inradiation therapy because it emits-
18 .At high altitudes the boiling point of water lowers because-
19 .The enzymes are killed-
20 .Nitrogen in water is commonly found in the form of :
21 .The ore of Aluminium is
22 .Which one among the following fules is used in gas welding?
23 .Neutrino has-
24 .Fementation of ethyl alcohol into acetic acid is done by-
25 .Which of the following is used as raw material for the manufacture of rayon?
26 .When or is heated generally in absence of air then process is called-
27 .One of the best solutions to get rid of non - biodegradable wastes is
28 .It is reported that there is an ongoing decrease in the pH value of ocean water because of global warming. It happens due to:
29 .Source of vitamin C is
30 .Water attains maximum density at-