Hi hayamhm,
Sorry I couldn't answer your language question, but let me say that it's
awesome that you can work in both languages. Good for you!
It wouldn't be
necessary to include a diagram of the ear, but it would certainly be helpful. I typed "diagram of the ear" into Google Images, and got several good hits. You can use one of those diagrams, but make sure that you cite your source, meaning that you include the source of the image in your bibliography. However, I think your best bet would be to find a physiology or anatomy textbook at your local library, and make a color copy of a good diagram from the book. Just make sure to include that book in your bibliography if you use the diagram!
If you haven't already, you can also include information about sebaceous glands and apocrine sweat glands, which are responsible for producing ear wax. Most people don't really know how ear wax is formed, so this would be interesting background information to include for your judges. As you mentioned, most diagrams don't include the glands, but they are located in the skin cells of the outer ear (including the external ear canal). You could mention this, and possibly even add it to the diagram yourself!
It sounds as if you are doing a wonderful job. Keep up the good work!
Cheers,
Heather
I think the safest thing would be to present everything in English, but this may be something to ask your teacher or to check with the science fair regulations. If all your instructions for the science fair are in English, I would assume that you should present in English. Is the regional science fair part of your French immersion program?