| Answer | Crossword Clue |
|---|---|
| TESTFOR | Determine the presence of, as in a lab |
| TESTFOR | Determine the presence of, as a chemical |
| ARSENIC | As, in the lab |
| BOHR | To whom Einstein wrote, "Not often in life has a human being caused me such joy by his mere presence as you did" |
| RETEST | Double-check, as in a lab |
| TESTFOR | Try to confirm the presence of, as a chemical |
