MIDTERM:

You will create an application that updates 3 stock prices every 5 minutes.
The application will know what 3 stocks you are concerned with because it will load them from a save.data or stock.txt file. (tr.ReadLine() and tw.WriteLine() are your friends here). 

This application will also fetch the local weather of a zipcode that is also stored in your data file and display the weather. 

C: doing all this with the stock symbols and zipcode hard coded into the application
B: Being able to update the zipcode and have it display data in the new zipcode next time it is open.
A: being able to do the above AND save the stock symbols dynamically into the save.data file. This means you can change which stock symbol to lookup and when the application starts next time it will look up the new stock symbols.