Portia，for ________ physics had once been very hard，turned out to be a physicist.
A．whom B．whose C．that D．which
(2009·陕西)Gun control is a subject ________ Americans have argued for a long time.
A．of which B．with which
C．about which D．into which
(2010·上海)Wind power is an ancient source of energy ________ we may return in the near future.
A．on which B．by which C．to which D．from which
She showed the visitors around the museum，the construction ________ had taken more than three years.(2011·江西)
A．for which B．with which
C．of which D．to which
Julie was good at German，French and Russian，all of ________ she spoke fluently.(2011·湖南)
A．who B．whom C．which D．that
Care of the soul is a gradual process ________ even the small details of life should be considered.(2012·湖南)
A．what B．in what C．which D．in which
