单项选择题
A．who was sold for a price as high as $ 5,000 B．who was famous for being the first painting elephant C．whose paintings sold for as high as $ 5,000 D．who started painting in the late 1980s
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