Warm-Up 9, Due Thursday, September 25, 12:00.
Warm-up questions usually either address material we handled during last class,
or material you were to read in preparation for class,
or you are supposed to answer questions based on your common sense alone.
Please answer each question in three or more sentences.
It is OK to answer 'I don't know' - but try to tell me why you are confused!
No late Warm Ups are accepted for any reason, and only those submitted electronically
through this web page (or by email, if the web page has technical problems)