A、It may exclude some people with other preference. B、It is better not to force them onto others. C、It is acceptable only among

Good morning. I feel happy to give you a speech today. No scenario is richer with the potential impoliteness than the everyday conversation, in which you can say the wrong thing, do the wrong thing, and occasionally spit on others when trying to pronounce nouns with German etymology.
    No worries. We’ve all had our moments with conversation etiquette mistakes.
    But just because these conversation etiquette mistakes happen across the board doesn’t mean they can’t be avoided. All it takes is good judgment, and a look at the most common conversation mistakes.
    Everyone has their own conversation topics of choice—work, office gossip or early 20th century smelting techniques.(20)There’s nothing wrong with having these topical preferences, just don’t force them on others. Let the conversation progress naturally: contribute where relevant and on-topic. We know you’re dying to participate, but don’t try to make some forced transition from American politics to your taxidermy collection. We’re not interested.
     (21)Technology has become a distraction for many and, of course, the phone is the worst offender. It’s an extension of you: it’s your life: you couldn’t live without it. We know. But be aware of this conversation etiquette mistake. No matter how important the text, the e-mail or the brick breaker score may be, checking your phone during a conversation is one of the most insulting gestures. In some countries, the "phone check" is punishable by death. And although in western culture it may only be looked at as a conversational faux pas, it’s still an ill-advised move.
    Know your audience. You can’t hide behind "I am who I am, no matter who I’m talking to. " Certain people require a certain type of conversation. Your boss sees the PG version, your friends see the R version and, if you’re lucky, you have the occasional X-rated with the spouse. But no matter what, you should always be tailoring the act for the audience. Just because the one about the Jehovah’s Witness and the rabbi gets a good laugh with your pals doesn’t mean you’ll get the same reaction at your aunt’s wake.
    It’s not only a conversation etiquette mistake, it’s also an alienating trait to exercise.(22)Even if you feel the urge to vocalize your greatness in comparison to others, do your best to suppress this competitive edge.
    If you have any question, please don’t hesitate to ask me.
20. What does the speaker say about having topical preferences?
21. What does the speaker think of technology?
22. What does the speaker suggest us do at the end of the talk?