I have two sentences:
1) Do something. 2) That (the action you performed) will make another thing happen.
I’m trying to combine these sentences into one, as they sound dumb to me when used separately. So far I think it should be like this:
Do something, which will make another thing happen.
but I’m not sure if it’s correct.
EDIT: Actually, I’m asking for a general rule, but the specific example is:
Press the button. That will make a list with country names appear.
Given the example that you provided, there are a lot of constructions you could use (that will work for many other cases as well):
Pressing the button will make a list of countries appear.
Press the button in order to see a list of countries.
Press the button, and a list of countries will be displayed.
Press the button if you want to see a list of countries.