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.
Soil is also made of minerals and water, but the humus makes minerals into plant food. Humus is still rotting, and so is covered with bacteria and fungi. When earthworms are tunneling, this is what they are eating.