Adding Combobox Items In Tabpages?

i am having 11 comboboxes and 11 tabpages in 1 tabcontrol each tab page having one combobox.i kept the name of combobox like combobox1,combobox2,combobox3.....and so on also there are other comboboxes in tabpages but they are of different name i had also kept the tag property of combobox from 0 to11 for each one now what i want to do is add the same item in all comboboxes for that i wrote code like:-

dim combos() as string=new string("A","B","C"....)
dim tp as tabpage
dim cnt as combobox
for each tp in me.tabcontrol1

[code]....

but this displays an error syntax like:"expression is of type System.windows.form.tabcontrol,which is not a collection type." i just want to add same items in combobox of each tabpage ..