例題017 People on the island of Yap dont need purses. They need a big stick and strong arms. A piece of Yap money has a hole in the middle, can be three or four meters high, and can weigh over a thousand kilograms. 3 A piece of Yap money h…

例文013 Human beings are blessed with three long-distance senses: seeing, hearing, and smelling. Of these, seeing is the longest distance sense. We can see streams of photons crossing the vacuum of space. 3 We can see streams of photons cr…