下列结构类型中,遇碱液呈红色或紫红色的是
A.羟基苯醌
B.羟基萘醌
C.羟基蒽酚
D.羟基蒽酮
E.羟基蒽醌
参考答案:E
Eric even didn't have ________common sense to dial the number 119 when ________fire broke out. [ ]
A. a; the
B. a; /
C. /; the
D. the; a
建设单位应在双方签订合同后()内,将其代表的姓名和职责书面告知监理单位。
A.5天,
B.5个工作日,
C.7天,
D.7个工作日