题目

.用来鉴定生物组织中蛋白质的试剂及其颜色反应是 A.苏丹Ⅳ染液，红色                 B.班氏试剂，砖红色  C.苏丹Ⅲ染液，橘黄色                D.双缩脲试剂，紫色 答案：B Will arrived late and missed the assembly．He ________ the traffic to be so heavy． [　　] A． hadn't expected B． wouldn't expect C． haven't expected D． wasn't expecting