解放前，邢台市区有家家打井的民俗，堪称一怪，这一民俗的形成与明朝太监（）有关。
A.王振
B.刘瑾
C.魏忠贤
D.冯保
参考答案：B
Look and answer. (看图，回答问题)
1. Did you go by bus?
_______________________________.
How did you go?
2. Did you go swimming yesterday?
what did you do yesterday?
一个包括40个题目的测验信度为0.80，欲将信度提高到0.90，通过斯皮尔曼一布朗公式的导出公式计算出至少应增加（）个题数。
A．40
B．60
C．100
D．50
