Once a hypothesis has been formed, it must be tested. This is done by conducting a carefully designed and controlled experiment<span>. The </span>experiment<span> is one of the most important steps in the scientific method, as it is used to prove a hypothesis right or wrong, and to formulate scientific theories.</span>
D. Think about other animals... even when they have opposable thumbs, they can't move and hold at the same time. We can RUN and hold food or weapons at the same time.
