Question

Define :- (a) Levelling
(b) crumbs ​

Answer 1

Answer:

Crumbs are the large chunks or cluster of soil, which may be of various shapes and sizes. ... When these crumbs are too large, these pores let the free passage of air and water through them, thus the water drains off very fast from the soil and leaves the soil dry.

Explanation:

Levelling or leveling is a branch of surveying, the object of which is to establish or verify or measure the height of specified points relative to a datum. It is widely used in cartography to measure geodetic height, and in construction to measure height differences of construction artifacts. Wikipedia