Tom and Fred were talking about the year 2050.
　　“What will 1 be like in the year 2050?” asked Tom.
　　“I don't know,” said Fred. “What do you think?”
　　“Well, no one knows. But it is 2 to guess,” said Tom. “In the year 2050 everybody will carry a pocket (袖珍) 3. The computer will give people the 4 to all their problems. We shall all have telephones in our pockets,5 . And we'll be able to talk to our friends all over the world. Perhaps(也许) we’ll be able to 6 them at the same time. Machines will do 7of the work, and people will have more8. Perhaps they will work only two or three days a week. They will be able to fly to the moon by spaceship and spend their holidays there.”
　　“I'm very 9to hear that. I hope to fly to the moon. And I hope I'll be able to live 10,” said Fred. “Won't that be interesting? Just like a fish.”

—Yes. Fifteen dollars.

若直线经过$A\left(1,0\right),B\left(4,\sqrt{3}\right)$两点，则直线$AB$的倾斜角为(      )