Task: Pos Tagging
Input (English): Sentence: The Alaskan tundra , for instance , has switched from being a net sink of carbon dioxide -- absorbing and storing more carbon from the atmosphere than it releases -- to " being a net source of CO2 ( releasing more carbon than is stored {{ ) }} because warmer winters have allowed dead plant matter previously stored in the soil to decompose and release CO2 . " 
Word: )
Output (English): -RRB-