土壤压缩
参考答案：
是指土壤在荷载下总容积减小的现象。
He often come to work early and he is ____ late for work.
A．usually
B．never
C．often
D．always
柯氏位摄影，中心线与听眦线夹角是（）
A.15°
B.23°
C.37°
D.45°
E.53°
