perennial: 89 phrases in 14 subjects |
Agriculture | 36 |
Biology | 7 |
Botany | 4 |
Construction | 1 |
Earth sciences | 2 |
Economy | 2 |
Education | 1 |
General | 10 |
Life sciences | 4 |
Medical | 6 |
Natural resourses and wildlife conservation | 1 |
Natural sciences | 12 |
Physics | 2 |
Statistics | 1 |