Lionel, I am not answering any of these any more - this question is almost exactly the same as the one you posted only a couple of weeks ago, where you had loads of answers all giving you the information that you are now asking for again. This is getting tedious.
I agree gen2- sometimes there are so many ands in a sentence that I feel the need to insert commas. An example might be: "John and Mary took their son and daughter to the park and ate fish and chips and jelly and ice cream as they walked..."