Amazon's Fire tablets are difficult to resist. They're inexpensive, well built and even have a dash of style. The new Fire HD 8\u00a0model, which comes in four colors, is especially good looking. Now the Fire tablets support Alexa, Amazon's virtual assistant.\nHere are two things you should know about Alexa if you're in the market for a Fire tablet.\n1. You can't wake Alexa with your voice\nAlexa on Fire tablets doesn't respond to wake words, unlike Amazon's Echo\u00a0and Echo Dot\u00a0devices. To access Alexa, you must long-press the tablet's home button, then speak your command. So, for example, rather than saying, "Alexa, what's the weather forecast?" you have to hold the button and then ask the question.\n2. Alexa on a Fire tablet does show and tell\nAmazon's other Alexa-enabled devices \u2014 Echo, Echo Dot, Tap\u00a0and Fire TV\u00a0\u2014 lack screens, which makes voice input imperative. Fire tablets, of course, have displays so Alexa can use the tablet screen to show as well as tell.\nWhen you ask Alexa, "What's the weather forecast?" on an Echo, you get a quick verbal response for the immediate future. On a Fire tablet, Alexa delivers the same verbal forecast, but it also shows an onscreen card of the forecast (such as a rain cloud), followed by a look at the upcoming week's forecast.\u00a0(Amazon's Alexa mobile appw for iOS and Android show you the same type of information cards.)\nAlexa's show-and-tell capabilities work with other types of information, too, including "Flash Briefings" news updates, sports queries, timers, Audible audio books, and calendar events.\n Amazon\nBut the show-and-tell isn't unlimited. When I asked the Fire tablet "What movies are playing this weekend?" Alexa simply rattled off the movie titles with no accompanying card.\nIn some cases, when you ask Alexa a question on an Echo or Echo Dot, your Fire tablet turns on and shows a relevant card. This works particularly well with some queries, such as weather forecasts, but not at all with others. And queries made on Amazon's Tap speaker didn't prompt a card to display on the Fire.\nReasons not to buy a Fire tablet\nAlexa is valuable, but it isn't enough of a reason to buy an Amazon tablet. You must be OK with Amazon's smaller selection of available Android tablet apps, as well.\nThe tablet also does not support Alexa commands for Spotify, which is disappointing. You can download the Spotify app and play music manually on Fire tablets, but you can't ask Alexa to play Spotify music for you. \u00a0\nWhy you might want an ereader instead of a Fire tablet\nA number of good reasons exist to buy a dedicated ereader instead of a Fire, or any other tablet.\nEreaders keep you focused on what you're reading, due to their truly, madly, deeply awful web browsing features. Ereader batteries can last much longer than tablets \u2014 as long as a month in some cases. That means you don't need to pack a charger for most quick trips. Ereaders can be extremely thin and light, too, such as my favorite option, the Kindle Oasis\u00a0($289 and up).\nReasons you should buy a Fire\nAmazon's latest Fire HD 8 tablet is a bargain at $90 for the 16GB version. You get a reasonably zippy 1.3 GHz quad-core processor and decent (though not particularly loud) Dolby speakers. Alexa is also a welcome, though not essential, addition to an already attractive, affordable tablet.