Given reviews from Amazon, classify those review based on their content into two classes: Negative or Positive.

[Q]: While old and out of print, this book is a very good way to learn the basics of photography. You have to ignore most of the references to digital cameras as the technology has changed a lot.
[A]: Positive


[Q]: I wouldn't recommend this book to an enemy. True, the information may be worthy, but the writing style and the narration were horrible. It is definitely NOT written (nor read) in a conversational manner. I'm willing to cut the narrator some slack as he was only reading what was written, however better inflection, phrasing, pauses, etc... would have greatly helped this otherwise tedious book.I couldn't even finish it. I suffered through the first 5 disks and after all that investment in time I couldn't bring myself to listen to the 6th. Its just that poorly written.I'll restate the fact that the message -- the information -- is worth hearing, its simply written in such a tedious manner that I couldn't stand to hear it through the end.I think I'll donate it to my local library.
[A]: Negative


[Q]: Seems to work as advertised. I opted for the non-battery back up, as my heating system has electric blower, so if power goes, heating system does not opearate. Battery/non-battery an individual judgment.Pros: "ready light" is not so bright as to be disturbing at night, if it is a visible location, as mine is; simple plug in operation; you can test alarm manually.Cons: its a bit larger than it looks in the pictures, so depending on where you mount it, might be unappealing to actually see the unit installed in a highly visible wall outlet. Instructions indicate not to mount behind curtains, etc. as air flow might be restricted. However, I could not find a "micro" unit.Observations: Obviously no safe method to test if the unit actually detects CO.Suggestion: put a pass-through female outlet in the unit, as it uses one plug in the typical wall outlet, and this feature would be helpful in a older home with fewer wall outlets.
[A]:
Positive