Professional relational database design requires that every table has a(n) ____ key field that stores unique values.

A blind Web site visitor relies on a screen ____ that reads the content aloud one cell at a time, which can make it difficult to understand how the information is organized in a table.

A. reader B. interpreter C. translator D. communicator

In the accompanying figure, the icon that shows the curved arrow that is pointing to the left will ____.

A. speed up the presentation B. slow down the presentation C. reset the clock to zero for the presentation D. reset the clock to zero for current slide