Although {TAIL ~ the above reaction} can also take {HEAD ~ place} in a gas phase, water necessarily exists in an actual environment as mentioned earlier 
Although { TAIL ~ the above reaction } can also take { HEAD ~ place } in a gas phase , water necessarily exists in an actual environment as mentioned earlier
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH