There are several exercises HERE. I linked to the last one on the page because it's one of the advanced ones, where your choices are a/an/the/no article. That seems to be what you're looking for. Some of the other exercises on that site only give a/an/the as the options, which I think is probably too easy for you.
Edit: There are more on this page from the same site.
Edit 2: And more here. Scroll down to the advanced ones.
Edit 3: And just a single advanced level one here.

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