ACRONYMS - Engineering

HI  EVERYBODY!
                                This activity is related to acronyms, which are very common in technical and scientific English. I'd like you to write the meaning of three acronyms. You'll be able to read the instructions in my comment. 
You must write the meaning of the acronyms going to 'comment' at the bottom of the picture. Click on 'comment' and you'll have two options: record and type. You must type the meanings. If you want, you can record them as well, that's optional.
Pat