— Paul, could you please _____ the TV? It's too noisy.

— Sorry, I'll do it right now.[ ]

A. turn up

B. turn down

C. turning up

D. turning down

根据《城镇燃气设施运行、维护和抢修安全技术规程》CJJ51－2006规定：在聚乙烯塑料管道进行开孔、封堵作业时，每台封堵机操作人员不得少于（）人

A.1

B.2

C.3

D.4