A test kit for preparing a chemical test pad used in testing for {TAIL ~ the presence} of occult blood in {HEAD ~ a specimen} 
A test kit for preparing a chemical test pad used in testing for { TAIL ~ the presence } of occult blood in { HEAD ~ a specimen }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD