Note that there are now several types of treatments and medical providers for which Medicare Part B pays 100% of the approved charges rather than the usual 80%. These categories of care include home health care, clinical laboratory services, and flu and pneumonia vaccines.
A giant covalent structure is a three dimensional structure of atoms held together (obviously) by Covalent bonds. These atoms are often all the same-so the elements Silicon and Carbon in the allotropes Diamond and Graphite are Giant Covalent structures.
The structure of a typical ionic solid - sodium chloride. How the ions are arranged in sodium chloride. Sodium chloride is taken as a typical ionic compound. Compounds like this consist of a giant (endlessly repeating) lattice of ions. So sodium chloride (and any other ionic compound) is described as having a giant ionic structure. You should be clear that giant in this context doesn't just mean very large.