Lizzie, age 12, regularly asks questions, such as, "What if everyone just got along?" and, "If I became a medical researcher, could I find a cure for cancer?" According to Piaget's theory, these questions suggest that Lizzie has acquired the ability to _______.
◦ mentally reverse actions.
◦ think symbolically.
◦ think abstractly.
◦ consider all relevant features of an object.