Iam 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, what am i

The answer to this question is the letter E

The us is first  the  u.s. economy  remains the  largest in the world  in terms of nominal  gdp. however, the  u.s. economy  loses its spot as the number one  economy  to china when  measured  in terms of  gdp  based on ppp. in these terms, china's  gdp  is $23.19 trillion exceeds the  u.s. gdp  of $19.42 trillion

Yes, it’s awesome
: )