| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | long period [prep] | 278 |
|
| 2 | long period of | 275 |
|
| 3 | longer period [prep] | 36 |
|
| 4 | longest period [prep] | 17 |
|
| 5 | long period in | 16 |
|
| 6 | long period during | 10 |
|
| 7 | long period for | 5 |
|
