A lot of language learning，________ has been discovered，is happening in the first year of life，so parents should talk much to their children during that period.(2012·安徽，29)

A．as B．it C．which D．this

The number of the audience，________ we had expected，was well over one thousand.

A．whom B．who C．which D．as

The man showed us such a heavy stone ________ no one could lift it.

A．that B．as C．which D．and

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

Julie was good at German，French and Russian，all of ________ she spoke fluently.(2011·湖南)

A．who B．whom C．which D．that

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

(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

(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

Portia，for ________ physics had once been very hard，turned out to be a physicist.

A．whom B．whose C．that D．which

After the flooding，people were suffering in that area，________ urgently needed clean water，medicine and shelter to survive.(2012·江苏，22)

A．which B．who C．where D．what