Ｔｈｅ Ｔａｐｐｉｎｇ Ｆｉｎｇｅｒ等４則
2005-04-29 00:00:00
科學(xué)大眾(中學(xué)) 2005年6期
What to do:Sit at the table or desk.Place your ear flat on top like this:Tap with your finger on the surface of the table about I foot(30cm)away from your ear.Tap hard.Then tap softly.
