Under these circumstances, {HEAD ~ the first and the second supporting members} are fixed to {TAIL ~ the first and the second axles} respectively, and the first and the second axles can provide pivoting activities 
are fixed to
Under these circumstances , { HEAD ~ the first and the second supporting members } are fixed to { TAIL ~ the first and the second axles } respectively , and the first and the second axles can provide pivoting activities
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH