1. Bones are flexible because they contain
fat tissue.
calcium.
collagen protein.

2. The function of the skeletal system is
to transport oxygen to the cells.
to produce blood cells.
to transmit information to the brain.

3. The shoulder contains a
hinge joint.
saddle joint.
ball-and-socket joint.

4. A saddle joint is located in
the knee.
the thumbs.
the neck.

5. Milk is a useful drink, because it contains
iron.
calcium.
oxygen.