Clue | Source | Date |
---|---|---|
Switch with another | Newsday | 30 Jun 2019 |
Gradually substitute | The Washington Post | 15 Jan 2017 |
Make a switch with | Newsday | 18 Jun 2016 |
Add gradually to a cycle | ||
Gradually substitute | ||
Gradually substitute | ||
Gradually substitute | ||
Add gradually during a cycle | ||
Add gradually, as crops to a field |