The protein synthesizing system is associated with________?

A and B horizon is called as________?

A plant virus must have: ________?

The removal of excess water from the ground surface is called:________?

Insects which develop their wings externally?

According to a latest research, Pakistan is predominantly a dryland country; 80% of its land area is arid and semi arid, 12% sub-humid and 8% under humid climate. Thus, soils of arid & semi-arid regions are vulnerable to a wide range of degradation process. As the case in arid and semi-arid climates elsewhere in south-central/southern Asia and Sub-Saharan Africa; ________ are among the major causes of soil degradation and desertification?