抛物线标准方程的性质有那些?
参考答案:
1.对称性;
2.顶点在原点;
3.交点在对称轴;
4.光束放在焦点通过抛物面反射后,成一束平行于对称轴的光线。
执行下面的程序,单击窗体后在窗体上显示的结果是 ______。Private Sub form_ Click() Dim Str1 As String, Str2 As String Dim Str3 As String, I As Integer Str1 = "e" for I = t To 2 Str2 = Ucase (Str1) Str1 = Str2 & Str1 Str3 = Str3 & Str1 str1 = Chr (Asc(Str1) + I) Next I Print Str3End Sub
A.EeFF
B.eEfF
C.EEFF
D.eeFF
已满()周岁的人故意伤害他人致人重伤或死亡的应当负刑事责任。