翻译 "n次根号a" 可以表达为 "nth root of a"。其中，"n" 表示根号的指数，"a" 表示被开方的数。所以，"n次根号a" 可以理解为 "a的n次方根" 或者 "a的n次根"

The English translation of "n次根号a" can be expressed as "nth root of a". Here, "n" represents the index or exponent of the root, and "a" represents the radicand or the number being rooted. Therefore, "n次根号a" can be understood as "the n-th root of a" or "the n-th root of a".