检查麻醉乙醚的馏程，下列不正确的是（）。
参考答案：使用水浴加热，水浴液面始终不得低于供试品的液面
门槛板内的插入件要用（）的方法固定。
A．点焊
B．定位焊
C．塞焊
A bond is needed when the bill of lading cannot be availed of the time of entry of the im- ported commodities. What does the sentence mean.（）
A. A bond is needed when the bill of lading is unavailable when the goods arrive at the destination.
B. A bond is needed when the bill of lading arrives at the port of destination.
C. A bond is not needed when the goods arrive at the destination.
D. A bond is needed when the goods arrive at the destination if there is no bill of lading at all.
