题目

下列可用于检测蛋白质的试剂及反应呈现的颜色是  A．苏丹Ⅲ染液；橘黄色                          B．斐林试剂；砖红色 C．碘液；蓝色                                        D．双缩脲试剂；紫色 答案：DPeople must ______ pouring dirty water into the lake. [     ]A. stop from B. be stopped C. stopped from D. stopped