Make Dropdowns and checkboxes readlonly

I have a page where customers can review there submitted information before they submit the form. I want to make all fields readonly so they can review the information and click a button that takes them to another page to edit the information. Its easy to make text fields readonly you just have to put it at the end of the short-code but when I try this with dropdown and checkbox fields it makes the information desappear. Does anyone know a way around this

https://ww.wp.xz.cn/plugins/contact-form-7/