Are you able to send a letter with pictures and sounds to someone somewhere in the world without a stamp(邮票) on it? Using a computer you can send e-mails quickly and easily. The post is much slower than e-mail. E-mail can send its message to the other side of the world in seconds.

    E-mail is easy to use and it saves time and money. The differences in time in different parts of the world do not matter when sending e-mail. It's twenty-four-hour service(服务) that you can send e-mail at any time of the day or night. No one has to be there to get e-mail. It does not matter if your friends are in beds when you send e-mail to them, or you are seeing a movie at the movie theater when they send e-mail back.

已知函数f(x)=$\sqrt{3}$lnx(x$\ge$1)，若将其图象绕原点逆时针旋转$\theta \in \left(0,\frac{\mathrm{\pi }}{2}\right)$角后，所得图象仍是某函数的图象，则当角θ取最大值θ₀时，tanθ₀=（　　）

下图为DNA分子结构的模式图，据图作答：