What subject is Mr. Pitt good at

A．half-brain sleep is found in a wide variety of birds
B．halt-brain sleep is characterized by slow brain waves
C．birds can control their half-brain sleep consciously
D．birds seldom sleep with the whole of their brain at rest

A．are capable of reliably recognizing the shape of an object
B．are close to exhibiting humanlike behavior
C．are not very different in their performance from those of the 50’s
D．still cannot communicate with people in a human language