海关为履行职责，可以依法佩戴武器，海关工作人员在履行职责时可使用武器。( )
参考答案：对
— Have you finished all your exercises?
— Yes, ________ is left. As a matter of fact, they are as easy as ABC.
A. nothing
B. not one
C. none
D. neither
CT增强中最常用的对比剂有
A．氧气
B．硫酸钡
C．碘油
D．离子型有机碘剂
E．非离子型有机碘剂
