{HEAD ~ Basic nitrogen contents} reach {TAIL ~ up to 2,000 ppm} while the total nitrogen contents reach 3,000 ppm or more 
reach
{ HEAD ~ Basic nitrogen contents } reach { TAIL ~ up to 2,000 ppm } while the total nitrogen contents reach 3,000 ppm or more
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH