It is ______ to believe that the quantity of water keeps unchanged when it is contained in two different glasses.

A．the first human-like entertainment robot developed by the Sony Corp
B．as capable as the QRIO of speaking, dancing, singing and walking
C．largest among all the entertainment robots developed by the Sony Corp
D．the first entertainment robot sold at the market by the Sony Corp

A．is excited when the robots are performing a traditional Japanese dance
B．keeps silent because he is a little unsatisfied with the new product
C．witnesses the creation of a series of entertainment robots
D．is an executive manager of Sony Corp.