服务处的主要职责是司门，提拿行李、代客办事等，同时负责饭店大门内外的（）。
A.安全和秩序
B.卫生和门讯
C.住客动态
D.信息资料
参考答案：B
The book was written in ______ easy English ______ even primary school students could understand it. [ ]
A. so; that
B. such; that
C. too; to
D. very; that
简述煤矿爆破作业引起瓦斯煤尘爆炸的主要原因。
