美国南北战争期间,联邦政府为扭转战局而实行的有力措施是[ ]
A.号召人民为维护联邦统一而战
B.颁布《解放黑奴宣言》和《宅地法》
C.停止驱赶印第安人
D.寻求外来援助
答案:B
They ________ have arrived at lunchtime but their flight was delayed. [ ]
A. will
B. can
C. must
D. should
扑救医院火灾时,应当运用“强攻近战固移结合确保重点,减少伤亡”等战术措施。