Willie has complained to the sales manager about the PC he bought _____ screen exploded for no reason.

A．which

B．where

C．whose

D．when

知识产权的特征主要包括( )。

A．客体的无形性、地域性、时间性

B．依法审查确认性

C．独占性或者排他性

D．非地域性

E．客体的有形性