( II )Magic Trick: Video TutorialWelcome, everyone, once again to Mike's Magic Class. Today I'm going to show you how to performthe coin-through-solid-glass trick.First, the trick.In my left hand I'm holding a small glass bowl, and in my right hand I have a coin. I place the coin inthe palm of my right hand. Now I'm going to hit my palm against the bottom of the bowl once, . . . twice, . . .three times. And presto! The coin has passed through the bottom of the bowl and is now inside it!Here's the explanation.First, make sure you hold the bowl at the top between your thumb and middle finger, like this. Then,after you hit the bowl with your palm for the second time, secretly move the coin from your palm to yourfingertips, like this. Then, when you hit the bottom of the bowl with your palm , the coin will jump fromyour fingertips, leave your left hand and fall into the bowl from above. But it will look like it passed throughthe bottom of the bowl.Remember, everyone, practice makes perfect, so don't worry if you can't do it right away. And I'll seeyou guys next time!( From:寂天文化) 
40. ( ) What do you learn from this video?
(A) The history of magic tricks.
(B) The secret behind a magic trick.
(C) Where and when you can see Mike perform.
(D) Why coins are good for use in magic tricks.