Don't forget   ____ the pen   ____ him.                         [ ]

A. to return, to    

B. to return, for    

C. returning, to    

D. returning, for

下面程序段的作用：在窗体上一个命令按钮。单击命令按钮后，将程序中字符串 "Welcome Home"中的字符全部大写输出，其后字符"Wel Back"全部小写输出。请填空。 Private Sub Command1_Click()a = "Welcome Home";b = "Wel Back"c = 【8】 + LCase(b)Print c End Sub