如图是由一个正方体和一个长方体拼成的，求它的表面积．（单位：cm）

    (D)

    How to talk to someone you don't know? It depends on the situation(情形).

    If one of your friends introduce you to a new friend, it would be OK to start talking about the person who introduces you. You may ask him/ her how they knew each other. Show you are interested in it, even if you aren't. Nod after he/ she talks. This will give you more time to listen to what he/ she says, and think about next question from his/ her talking.

    Now if you go to a class on the first day where you do not know anyone, the first thing you should remember is not to be shy when talking to other people. You may remember when you were in the first or second grade, someone would just walk up to you and talk to you. Be open, but think before you talk.

    When it comes to meeting people face to face for the first time, find a situation which both of you are in. Maybe you are sitting next to each other. Maybe the other person says something you don't understand. Find a situation that seems proper (恰当的). Start with a simple conversation. It may seem strange at first. But the more you talk and take action with them, the more they will like you.

读美国图，完成要求．

函数$f\left(x\right)=x·\left(\frac{1}{2^x-1}+n\right)$为偶函数，则实数n的值为____ ．