题干
_________ he was very tired, he continued working in his office.
A：Since
B：Although
C：As soon as
D：Because
答案(点此获取答案解析）
B
_________ he was very tired, he continued working in his office.
A：Since
B：Although
C：As soon as
D：Because
，丁香油酚的结构简式为： 
，下列关于两者的说法正确的是（ ）