裂隙
参考答案：
岩石受地壳运动及其它内外地质营力作用影响产生的空隙。
艾泼斯坦方圈
The MINIMUM acceptable size for a towing bridle would be that size in which the safe working load (SWL) of each leg of the bridle is equal to（）.
A.one-half the SWL of the main towing hawser
B.three-fourths the SWL of the main towing hawser
C.that of the main towing hawser
D.twice that of the main towing hawser
