( )是应急活动的基本原则。
A.场内指挥B.统一指挥C.场外指挥D.技术指挥
参考答案:B
解析: 无论是采用哪一种指挥系统,都必须实行统一指挥的模式。
Some of the roads were flooded, _______ made our journey more difficult. [ ]
A. which
B. it
C. what
D. that
Jimmy felt terribly sorry because he took his deskmate's math book away__________[ ]
A. in mistake
B. by mistake
C. in trouble
D. by wrong