妊娠高血压综合征最基本的病理变化是（）

A.胎盘绒毛退行性变化

B.水钠潴留

C.全身小动脉痉挛

D.弥漫性血管内凝血

E.肾小管重吸收功能降低

I do every single bit of housework _______ my husband Bob just does the dishes now and then.

A．since

B．while

C．when

D．as