The two main types of load cells used in mooring tension gauges are（）.

A.distortion and compression

B.hydraulic and mechanical

C.magnetic and applied torque

D.frictionless and hydraulic

减压围井法具体做法有以下几种：（1）无滤围井；（2）无滤水桶；（3）（）。

A.土袋围井

B.减压井

C.减压沟

D.背水月堤