In addition, some of the materials used in IQ tests may be totally foreign to certain cultures, thus creating inequalities and biases. It is interesting to note that IQ scores have increased so much over the 20th century that most of today's test takers would be considered 'geniuses' by 1900 standards.
Digital subscriber line (DSL; originally digital subscriber loop) is a family of technologies that are used to transmit digital data over telephone lines.
The opposite of ADSL is SDSL, which stands for symmetrical digital subscriber line. SDSL provides a high-speed data connection that gives equal priority to upload and download speed. Other types of DSL include Internet protocol subscriber line, rate-adaptive digital subscriber line, Uni-DSL and Etherloop.