___________ his poem, he didn’t dare to submit it to the professor.

A．Not having polished

B．Having not polished

C．Not polished

D．Not being polished

今年3月底，在我国几个省市发现新型H7N9禽流感病例．专家提醒，食用禽产品时要充分煮熟．从传染病的预防来看，该措施属于（　　）

A．控制传染源

B．保护易感者

C．切断传播途径

D．消除病原体