Hello!I'm a word.I have three letters.My first letter is in

Hello!I'm a word.I have three letters.My first letter is in "soon"but not in "noon",
my second is in"rose"and also in"rise",my third is not in "pencil"but in"paper",my whole is a place where there is a lot of water.I am the twin sister of the word"see".Who am I? 判断句子对错：1.The word is a kind of animal.( )2.The first letter is "m".( )3.The second letter is "e".( )4.The third letter is "r".( )5.This word is "sea".( ) 谜底------