The interior of each of the toys includes a gyroscope, which when operated creates considerable rotational momentum, tending to resist {HEAD ~ the movement} of the toy by {TAIL ~ the user} 
by
The interior of each of the toys includes a gyroscope , which when operated creates considerable rotational momentum , tending to resist { HEAD ~ the movement } of the toy by { TAIL ~ the user }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL