预松开时间 Pre-release time

预算松弛 Budgetary slack ; Budget Slack

土岩预松 preliminary loosening of sediments

预应筋松弛 relaxation of prestressed tendon

松弛预算 slack budget

预防骨质疏松 preventing osteoporosis ; prevention of osteoporosis

钢筋预应力松弛损失 loss due to tendon relaxation

预算松弛治理 Budget slack management

预应力松弛 relaxation of prestressing