The CO and {TAIL ~ H2} are reacted under high pressures to produce {HEAD ~ methanol} 
The CO and { TAIL ~ H2 } are reacted under high pressures to produce { HEAD ~ methanol }
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD