Before joining the Department of Defense, Mr． Panetta as director of the CIA fro
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Before joining the Department ofDefense, Mr．Panetta _______ as director of the CIA from February 2009 to June 2011．
A． would serve B． served C． was served D． hadbeen served
试题答案
【答案】
B
【解析】考查时态。根据本句的时间状语：fromFebruary 2009 to June 2011说明在过去的时间发生的事情，使用过去时即可。Serve没有被动语态。故B正确。