◎ 题干
—Flight 551 for Dallas ________. I must be off now.  
—Have a pleasant trip then.
[     ]
A. is being announced  
B. has announced
C. was announcing  
D. had been announced
◎ 答案
查看答案
◎ 解析
查看解析
◎ 知识点
    根据魔方格专家分析,试题“—Flight 551 for Dallas ________. I must be off now. —Have a pleasant trip then.[ ]A. is being announcedB. has announced C. was announcingD. had been annou…”主要考查了你对  【现在进行时的被动语态】  等知识点的理解和应用能力。关于这些知识点的“档案”,你可以点击相应的链接进行查看和学习。