可先采用按摩和局部抗生素滴眼等保守治疗1～2周后无效可行泪道探通的病为（）

A.泪小点完全膜闭

B.泪点缺如

C.鼻泪管阻塞

D.先天性泪囊膨出

E.泪点和泪管完全缺如

Fire protection regulations for towing vessels allow all of these types of fuel piping，EXCEPT（）.

A.steel

B.aluminum in an aluminum-hulled vessel

C.schedule 80 fire resistant plastic pipe

D.nickel-copper，copper-nickel or annealed copper