Related Clues:

• Ruby or Sandra
• Wallace of 'E.T.'
• See 17-Across
• Poor grade
• Low mark
• Gidget portrayer Sandra
• 'Look at Me, I'm Sandra ___'
• Insect repellent ingredient
• Fourth in a series
• See 56-Down
• Singer Joey with the 60's Starliters
• Just-passing grade
• Low grade
• River to the North Sea
• Not a grade to be proud of