Part of the Arabian Desert, the Rub al-Khali, meaning âempty quarterâ in Arabic, is the largest region of continuous sand in the world, and the driest. It lies in a structural basin and stretches across an area of roughly 250,000 square miles (650,000 square kilometers.)
How do ciliates move?   Answer   Ciliates, a unicellular protozoa, use their cilia, tiny hair-like organelles, to move around. What are ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid called? Ependymal cells are cells that line the central cavities of the brain and spinal cord. They are ciliated and act as a semi-permeable lining between the cavities and normal tisâ¦sue.
  The fluid that circulates through the ventricles of the brain, the central canal of the spinal cord and the subarachnoid spaces is cerebrospinal fluid (CSF). CSF is an u â¦ ltrafiltrate of blood plasma, produced in the choroid plexus in the ventricles and basal cisterns.