单项选择题
Water allowed to accumulate in the hydraulic system oil will cause an oxidation process producing by- products which are normally （）.
A.gums, acids, and varnishes B.removed by cellulose type filters C.neutralized by oil additives D.not removed by absorbent filters
单项选择题 If an anchor windlass has been idle for some time, you should （）.
单项选择题 The color of the flame on a halide torch without any refrigerant present is （）.
