sand extraction

基本解释

The inference can be proved by the artificial oil mixing test and oil-bearing sand serial extraction.
通过原油混合试验和油砂连续抽提试验证实了混源油的推测。
The variations of flow pattern cause headwater erosion, and the sand gravel extraction will result in comprehensive adjustment of riverbed , affecting riverbed stability.
水流流态变化引起溯源冲刷，进而导致河床全面调整，影响河床稳定。
Planning sand extraction scheme in accordance with potential channel change and combining channel modification with sand extraction can improve navigation condition to a certain extent.
科学合理规划采砂方案，顺应河床演变趋势，将整治河道与采砂疏浚河道有机地结合起来，可除害兴利，在一定时期内和一定程度上改善航道条件。

Unable to stop Canadian oil drilling and tar sand extraction programs, environmental groups are now trying to block any pipeline that is proposed out of the oil producing regions.
FORBES: Keystone XL: Voting for the Stone Age
Major activities in the area are agriculture, forest management, sand and gravel extraction, industry (diverse types), and ecotourism.
UNESCO: EDUCATION