adjustable weir crest的用法和样例：
- Relationship between head above weir crest and minute prssure on weir surface
- Slip form construction technology of new emergency spillway weir crest in Huangbizhuang reservoir
- The stone buildings perch on a hill crest.
- It has novel seal structure and adjustable overflow weir plate.
- He reached the crest of the hill before dawn.