单项选择题
A．a B．an C．one D．another
A．only human beings have problem-solving intelligence B．a person’ s memory is different from a computer’ s in every respect C．animals are able to solve only very simple problems D．animals solve problems by instincts rather than intelligence
A．moving some part of their body B．stopping what they are doing to listen C．directing the orchestra playing it D．wishing that they could conduct music properly