| Answer | Crossword Clue |
|---|---|
| ENC | It's added to an env. |
| PTA | School gp. that sometimes has an "S" added to its name |
| dopant | an impurity added usually in minute amounts to a pure substance to alter its properties (as conductivity) |
| antifreeze | a substance added to a liquid (as the water in an automobile engine) to lower its freezing point |
| antifreezes | ANTIFREEZE, a substance added to a liquid (as the water in an automobile engine) to lower its freezing point |
| ENCL | It's inside an env. |
| ENCL | It's in an env. |
| ADDR | It's written on an env. |
| LTR | It's put in an env. |
| ATTN | "It's for you," on an env. |
