阅读程序：
Sub Form_Click( )
a = 10: b = 15: c = 20: d = 25
Print a; Spc(5); b; Spc(7); c
Print a; Space(8); b; Space(5); c
Print c; Spc(1); "+"; Spc(1); d;
Print Spc(1); " = "; Spc(1); c + d
End Sub
运行上面的程序，单击窗体后，第三行输出结果是________。
A．■20■+■25■=■45■
B．20+25=45
C．10 15 20
D．20 25 45
