今天我们要学的词组是backup。作为形容词,backup的意思是后备,替代。媒体报道说,布什总统实施新的伊拉克计划之后,一些州长在白宫询问布什和参谋长联席会议主席Peter Pace有没有后备计划,"A group of governors asked President Bush and chairman of the Joint Chief of Stuff Pet...