A child is playing at the beach. She pours an equal amount of sand into both a short, fat container and a tall, thin container.
When asked which container holds more sand, the child points to the tall, thin container. This response suggests that she is most likely in the ________ stage of cognitive development. Group of answer choices
Several vaccines are made by taking toxins and inactivating them with a chemical (the toxin, once inactivated, is called a toxoid). By inactivating the toxin, it no longer causes disease. The diphtheria, tetanus and pertussis vaccines are made this way.
