Thus, the calculator-abacus was invented. In Chinese history, the origin of the abacus can be traced back to the Spring and Autumn Period, 600 B.C., and it was widely used before the invention of Arabic numerals appeared in the world. The abacus has proven to be one of ancient Chinaâs greatest inventions. Before the abacus was invented, people used small wooden sticks as calculation chips to make calculations. (Image: Derrick Coetzee via Flickr/ CC0 1.0))
Social anxiety disorder, also called social phobia, is an anxiety disorder in which a person has an excessive and unreasonable fear of social situations. Anxiety (intense nervousness) and self-consciousness arise from a fear of being closely watched, judged, and criticized by others.
Anxiety Anxiety is an emotion characterized by feelings of tension, worried thoughts and physical changes like increased blood pressure. People with anxiety disorders usually have recurring intrusive thoughts or concerns. They may avoid certain situations out of worry.