Why do you want to say sofa in the first place?

There is such an explanation, the first reply is called the second floor, referred to as SF, and the English name of the sofa is SF, referred to as SF. Or the pinyin of the sofa is shā fā, and the abbreviation is also sf.

In fact, I understand that the first reply to the post has a high degree of attention, and there are people who have grabbed a good position, and in reality, a good position is naturally a sofa, followed by a bench, and then a floor.

It is always the first person to be seen in the place where the reply is posted, and he is always the first person on it. Priority is given to sitting, so it is called a sofa. The second one is gone, so I can only make a bench.