You should do all of the following to prepare for an extemporaneous speech, except: a. commit your speech to memory b. make a keyword outline c. write your main points on notecards d. rehearse carefully

You should do every option in an extemporaneous speech except a. commit your speech to memory.

Memory is very important when giving a speech, but it is not the most reliable tool you have in your presentation. Nerves and stage fright could be some of your most powerful enemies when you are on the spotlight, and they will always attack your memory first.

So, writing some notes, making a keyword outline and rehearsing carefully are the best options to give your best speech!

because each is self-sufficient.  

yes they most likly are and have planed t try to bring human life and supplies there also(due to global warming and other harmful resorces)