黄帝和炎帝两个部落联盟结合在一起，经过长期发展，形成了日后的[ ]

A、白族

B、蒙古族

C、满族

D、华夏族

The news________us so much that all of us were________at it. [      ]

A. astonished；astonished

B. astonishing；astonishing

C. astonished；astonishing  

D. astonishing；astonished