I don't want __________any misunderstanding.[ ]

A. being

B. there being

C. there to be

D. there having been

特高压输电线路的绝缘可以分为哪两类（）。

A.导线与杆塔或大地之间的空气间隙

B.绝缘电缆

C.绝缘子

D.绝缘线