The most abundant metal in the earth’s crust and toxic to plants in low concentration is________?

Those insects which lives in groups, clones or tribes form are called________?

Calf diphtheria is a disease caused by ________?

The angle between a head regulator and entrance of water, for smooth entry of water in a canal is kept as ________?

The piles driven in low bearing capacity soil which does not rest on hard rock but bears the coming load due to side resistance is called ________?

The resistance of a soil at various moisture contents to mechanical stresses or manipulations: