某研究性学习小组设计下列实验方案,验证铁、铜、银三种金属的活动性顺序,每种方案所需试剂如下(反应所得产物可用作试剂进一步反应),其中不可行的方案是( )
A:铜、硝酸银溶液、氯化亚铁溶液
B:银、铜、氯化亚铁溶液
C:铁、银、氯化铜溶液
D:铁、硝酸银溶液、氯化铜溶液
All my classmates were _______ my idea that we should go on an outing next week.
一个直角三角形有两条边长为3,4,则较小的锐角约为( )
- Excuse me. Do you know __________?
- Well, go along this street and turn right. There’s one on the left.
已知:如图所示:
作出△ABC关于y轴对称的△A′B′C′,并写出△A′B′C′三个顶点的坐标.