{HEAD ~ The leveling apparatus} can keep a horizontal level of the upper swing structure against {TAIL ~ an inclined ground} 
{ HEAD ~ The leveling apparatus } can keep a horizontal level of the upper swing structure against { TAIL ~ an inclined ground }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL