【正确答案】 D

【答案解析】[解析] 画线词operative为形容词，意为“运作的”。A项flowing意为“流动的”；例：His handwriting was flowing and graceful. 他的字写得流畅优美。B项moving意为“移动的”；例：It was a moving moment for me. 对我来说那是一个感人的时刻。C项rotating意为“转动的”；例：The house was full of these rotating beams of light. 屋子里满是旋转的光柱。D项working意为“运作的，工作的”；例：For doctors the working day often has no end. 医生常常没有下班的时候。故选D。