Teachers are categorized in four main classes in Bangladesh at University level. The ascending rank of teacher is Lecturer, Assistant Professor, Associate Professor and Professor. The initial position Lecturer is generally enrolled as the top student of the class. Master's degree is required for normal university level Lecturer.
Humus soil is soil made up of decayed organic material. Popularly, it refers to soil that is light in texture, dark brown or black in color, and sweet-smelling.
In nature humus is constantly introduced into soil as plant debris, dead animals, and other organic matter that decomposes on the ground. Through the alchemy of bacteria, fungi, and other resident micro-life activity, this organic material is reduced by degrees to its soft, spongy essence, called humus.