What's that in the tree,can you see?There must( ) some birds( ) in itA,are;sitting B be;sit C have;sitting D.be;sitting
问题描述：
What's that in the tree,can you see?There must( ) some birds( ) in it
A,are;sitting B be;sit C have;sitting D.be;sitting
答
D
答
c情态动词家完成时
答
D
there must be表肯定的推测
sitting in it 现在分词短语作定语
百度教育团队【海纳百川团】为您解答,若帮了您,记得采纳哦-,0
答
A 这是There be固定结构
望楼主采纳 祝你学习进步 更上一层楼 嘻嘻