IVDSA的中文全称是（）
A．动脉DSA
B．静脉DSA
C．全身DSA
D．能量DSA
E．动态DSA
参考答案：B
After being questioned by the police , he admitted ____in the supply of drugs over a 20-year period.
A． to be involved
B． being involved
C． involved
D． been involving
______是SNMP网络管理系统的核心。
