有了人类，就有了人类社会。我国境内的人类活动至少出现在[ ]

A．三、四百万年前

B．170万年前

C．70——20万年前

D．公元前21世纪

Four years ago, quitting the artistic director of American Ballet Theatre, Baryshnikov found the White Oak Dance Project.

A．have quit as... was founding

B．having quit as... had founded

C．being quit as... founded

D．having quit as... founded