The most productive means of word-formation are ( ), compounding

The most productive means of word-formation are ( ), compounding and conversion.
【正确答案】：AFFIXATION
【题目解析】：The most productive means of word-formation are affixation, compounding and conversion.构词法中最为多产得方式是词缀法、复合法和转类法。故答案为affixation。