Therefore, {TAIL ~ the grass} can be mown, without leaving {HEAD ~ any uncut grasses}, so as to have a good finish 
Therefore , { TAIL ~ the grass } can be mown , without leaving { HEAD ~ any uncut grasses } , so as to have a good finish
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH