_____, the Yellow River is the second longest fiver in China and it's the birthplace of Chinese culture.[ ]

A. As a result        

B. It is said  

C. As well as        

D. As we know

甲状腺细胞摄取碘通过（）

A.主动转运

B.易化扩散

C.单纯扩散

D.入胞作用

E.出胞作用