| A | B |
|---|
| antenna | One of the two long, thin feelers on the head of many insects and of some water animals such as lobsters. |
| balance | To stay in a steady position without falling. |
| boulder | A large, rounded rock, resting on or in the ground. |
| cliff | A steep, high rock face with a sharp drop to the ground below. |
| joint | The place where two parts meet or come together. |
| machine | An object that is used to do certain kinds of work. |
| motor | An object that provides the power to make something move or do work. |
| muscle | A part of the body that can be stretched or tightened to make the body move. |
| planet | A large object in space that moves in a regular path around the sun or some other star. |
| slope | A surface, a line, or a piece of land that is higher at one point than at another. |
