前功尽弃

小D唱ABC Song，唱得很认真：

“A B C D E F G

  H I J K L M P (where is my N and O?)

  Q R S T U V

  W X Y and Z

Now I know my A B C

How I wonder what you are?” (Have you heard of Twinkle Twinkle Little Star? hahahaha... )