These structural materials must be able to withstand tremendous forces that affect an organism support the mass of the body and all of the muscles and organs that are part of the body remain strong under the stresses of locomotion, such as when the feet strike the ground, sending the force of the impact through the body frame be strong at the 
(the feet; strike; the ground) (These structural materials; to withstand; tremendous forces that affect an organism support the mass of the body and all of the muscles and organs) (tremendous forces; affect; an organism support the mass of the body and all of the muscles and organs) (sending the force of the impact through the body frame; be; strong at the; T:when the feet strike the ground) (the muscles and organs; are; part of the body)
the feet These structural materials tremendous forces sending the force of the impact through the body frame the muscles and organs
strike to withstand affect be are
the ground
tremendous forces that affect an organism support the mass of the body and all of the muscles and organs
an organism support the mass of the body and all of the muscles and organs
strong at the T:when the feet strike the ground
part of the body