单项选择题
A．intellectual achievement B．competitive personality C．social backgrounds D．social and political skills
A．bought them a lot of art supplies B．made them excited at the beginning C．taught them to hold a paintbrush with their trunks D．reinforced the desired behaviors with rewards
A．She used a stick to draw in the dirt. B．She spent much time in the dirt. C．She stimulated herself every day. D．She painted with her keeper's art supplies.