根据《建筑设计防火规范》厂房的防火间距规定,甲类厂房与民用建筑之间的防火间距不应小于()m。
A.15
B.25
C.30
D.50
参考答案:B
---Is this ________ book?
---Yes, it's ________ English book.[ ]
A. a; a
B. an; an
C. an; a
D. a; an
He ________ have sent the email at an earlier time, but there was something wrong with the network.[ ]
A.must
B.should
C.could
D.might