A. heavy B. easily damaged C. affected by temperature D. costly relative to the strength ratio
A. at all times B. in the bottom return mode C. in the volume reverberation mode D. only when there is no current
A flashing amber light B. A fixed red light C. A white flag raised and lowered vertically D. A flashing white light
A. one control B. two controls C. three controls D. none of the above
A. increasing the righting moment B. decreasing the vessel's displacement C. increasing the reserve buoyancy D. shifting the CG (center of gravity) off center
微信支付 
支付宝支付