How can I insert my sortedlist into a listbox?

I am new to C# and currently using a sortedlist<string, int> in order to store values that I need to display in a listbox (according to my uni, this is how I need to do it). I have tried quite a few things however I am struggling to get both the key AND value into a listbox. Would anybody be able to give me some guidance on how I can go about doing this?