A base 10 of {HEAD ~ the work platform} is supported with {TAIL ~ a bracket} 9 at, at least, three supporting portions 
A base 10 of { HEAD ~ the work platform } is supported with { TAIL ~ a bracket } 9 at , at least , three supporting portions
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH