Here is a worksheet on the use of meantime and meanwhile. As Paul Brians, the author of Common Errors in English Usage (to which he generously allows access at no charge at his Washington State University web page), from which this worksheet is adapted, observes, most people use these words interchangeably. Merriam-Webster appears to think so, identifying them as synonyms to each other in the electronic version of its Collegiate Encyclopedia (11th Edition). At the same time, Merriam-Webster designates both words, when separated by dashes (i.e. mean-time and mean-while) as nouns.
Yet, as Professor Brians also points out, some usage experts designated specific uses for each of these adverbs and nouns. It is that designation that drives this worksheet, which is a full page and features a reading of two longish sentences and five modified cloze exercises. This might be a useful exercise for opening a discussion about, well, English usage; that in turn might lead to a review of a usage manual to familiarize students with the, well, usefulness, of such a book.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.
Mark's Text Terminal 