“If you agree with me，please Dianzan.”Do you know Dianzan is one of the most popular words on the Internet？When you think someone's ideas are right，when you think someone's articles are 1，or when you are moved by what someone writes，you can

    click （点击）the praise sign. Anyhow，clicking the praise sign 2that you agree with someone or praise someone.

    Dianzan is a kind of Chinese Internet language.People 3 use it when they surf the Liternet.There is a function（功能）of Dianzan in the QQ space.The QQ space has had the function 42010.It didn't become very popular until Sina blog（新浪博客）5the function of Dianzan.In recent years，it has become more and more popular.When the 2015 New Year came，Chinese leader Xi Jinping used the word Dianzan to praise and 6his thanks to the great Chinese people.

    Websites can know how many people support some ideas 7counting how many people click the praise sign.Experts can know 8teenagers are caring about through what they click the sign for.That can help them solve teenagers'9.

    Clicking the praise sign is really a（n） 10thing.Have you ever clicked the sign for anybody on the Internet

（1）f（x₁+x₂）=f（x₁）f（x₂）

（2）f（x₁•x₂）=f（x₁）+f（x₂）

（3） $\frac{f\left(x_1\right)-f\left(x_2\right)}{x_1-x_2}$ ＞0

（4）f（ $\frac{x_1+x_2}{2}$ ）＜ $\frac{f\left(x_1\right)+f\left(x_2\right)}{2}$

（5）f（ $\frac{x_1+x_2}{2}$ ）＞ $\frac{f\left(x_1\right)+f\left(x_2\right)}{2}$

（6）f（﹣x）=f（x）．

当f（x）=lgx时，上述结论正确的序号为____．（注：把你认为正确的命题的序号都填上）．

①把遵守党的组织纪律，作为自己行动的出发点和落脚点

②把内化于心的规矩外化于行，自觉践行党的优良传统

③坚持党中央的集中统一领导，时刻牢记这一根本政治规矩

④加强自身建设，坚持从严治党