NOTE1: butterfly，蝴蝶的意思，发音要领要注意。
NOTE2: It means that I feel a little bit nervous. 2） It has cost me an arm and a leg.
NOTE1: 注意an arm的连读。
NOTE2: It means that it is very expansive. 「世博ＶＯＡ」洗耳恭听，两个句子小菜一碟！ Here is a story: Just the other day, Andy went to a jewelry store to choose a diamond ring for his girlfriend to make a proposal. Finally he got the one he wanted. It was nice, like all other precious jewelries, it cost Andy an arm and a leg. On that day he dated the girl out, Andy got butterflies in his stomach. However, nervousness is not a word in Andy's dictionary. He soon calmed down and presented the ring to her and said, will you marry me? Thanks to his courage and that dazzling（耀眼的，夺目的） ring, she accepted it! And that day became a red-letter day for Andy. 1） I'm getting butterflies in my stomach. 我有些紧张。
2） It has cost me an arm and a leg. 它很贵。 「请你猜猜看」挑战自我，情景抢答也刺激！ Here are three situations: S1. Your friend bought a new BMW（宝马车）, and you asked how much it was. He said it was very expansive. Is there another way to express that? S2. Your friend lent the car to you for one day. You drove it as carefully as possible in order not to make a scratch on it. What do you feel when you drove it? S3. Mary is doing a physical experiment. And now, it is the last step. She is eager to see the result. How's her feeling now?