在锌锅、气刀区域进行作业时，必须佩戴好专用劳动防护用品。
参考答案：对
We could have asked someone to carry out the plan privately without it ________.[ ]
A．was known
B．knows
C．being known
D．be known
慢性泪囊炎最常见的有效治疗是（）
A.鼻腔泪囊吻合术
B.泪道激光术
C.泪道探通术
D.泪囊摘除术
E.泪道置管术
