| Answer | Crossword Clue |
|---|---|
| READ | Do one of the three R's |
| RITHMETIC | One of the three R's. |
| READING | One of the three R's. |
| RDG | One of the three R's |
| ARITH | One of the three Rs (abbr.) |
| REUSE | One of the three "green" R's |
| ARITH | One of the three R's: Abbr. |
| RECYCLE | One of the three green R's |
| REUSES | Practices one of the environmental three R's |
| REUSE | One of the three R's of environmentalism |
| REDUCE | One of the three R's of environmentalism |
| LONELIEST | "One is the ... number that you'll ever do" (Three Dog Night lyric) |
