| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | served as | 349 |
|
| 2 | served as | 347 |
|
| 3 | serve as | 330 |
|
| 4 | serves as | 247 |
|
| 5 | to serve as | 231 |
|
| 6 | serve as | 162 |
|
| 7 | serving as | 143 |
|
