U. S. Army soldiers from the 27th Infantry Regiment pull a bobcat tractor out of the mud at their mountaintop position at Observation Post Mustang in Kunar Province, Afghanistan.
在阿富汗库纳尔省的野马观测站，美国陆军第27步兵团的士兵正在山顶将轻型拖拉机从淤泥中拖出来。
2
During 1981-1987, the fixed positionobservation was conducted in different patterns of multiple cropping system of paddy fields.
1981年至1987年，对稻田不同多熟种植方式进行了定位观察。
3
An explicit functional relation of the point position variance of angular resection with observation value was derived.