Related Clues:

• I or E, e.g.
• One of sequoia's five
• K-6, in some districts: abbr.
• Y, sometimes
• Grades K-6 (Abbr.)
• Na or Cl, e.g.
• One of five different ones in 'sequoia'
• Something on a table: Abbr.
• One of an au pair?
• Primary: Abbr.
• Na, Ne, Ni or No
• B or C, but not A or D: Abbr.
• Grades K-6, perh.
• School for 7-year-olds, briefly
• Part of 51-Across: Abbr.