Hi,
Welcome to the ODK forum, @Kate_Seong We're glad you're here. When you get a chance, please introduce yourself here. I'd also encourage you to add a real picture as your avatar because it helps build community!
Please find attached a modified version of the form. Additionally, since you have a long list of the administrative units, you should try to use an external csv file.
Thanks
dataentry_test.xls (123.5 KB)