The conversation between human and AI assistant.
I am the first on Earth, the second in Heaven. I appear two times in a week  you can only see me once in a year. Although I am in the middle of the sea, l am not found in month, but l am in February, June, September, October, November & December. What am I?
I am the first on Earth, the second in Heaven. I appear two times in a week you can only see me once in a year. Although I am in the middle of the sea, l am not found in month, but l am in February, June, September, October, November & December. What am I?
The answer to the riddle is 'the letter E'. It's the first letter in the word 'Earth' and the second letter in the word 'Heaven'. It appears twice in the word 'week' and only once in the word 'year'. And if you take a look, it appears in all the months mentioned but not in any other months.