[speaker001:] There are so many people that the tickets are all sold out!
[speaker002:] Luckily we got the last two.
[speaker001:] Look, Danny. The Four Great Inventions!
[speaker002:] Gunpowder, compass, the paper making, and the printing.
[speaker001:] I really admire those who made such great inventions!
[speaker002:] May, I don't see why they are great. They are just simple things.
[speaker001:] They look simple today. But they were milestones in their times.
[speaker002:] Milestones? May, you must be kidding.
[speaker001:] Just think Bill Gates, those inventions are as important as the windows system.
[speaker002:] Well, I suppose the ancient inventors made a lot of money out of them.
[speaker001:] No, quite the contrary.
[speaker002:] Why? Didn't you say that they were milestones?
[speaker001:] Yes, but they went to the public without any patent protection.
[speaker002:] Well, their inventors were not as clever as Bill Gates.