堤坝滑坡（背水脱坡）的抢护原则是“（），恢复堤身稳定”。
参考答案：消除渗水压力
The law of over－learning explains why cramming (突击学习) for an examination, though it may result in a passing grade, is not a ________ way to learn a school course.[ ]
A. convenient
B. demanding
C. satisfactory
D. swift
稀释与接种法测定水中BOD5时，某水样呈酸性，其中含活性氯，COD值在正常污水范围内，应如何处理？
