that only 13 percent of children bike,walk or( otherwise) ge

題目：

that only 13 percent of children bike,walk or( otherwise) get themselves to ...問 otherwise詞性
But today,the Centers for Disease Control report that only 13 percent of children bike,walk or( otherwise) get themselves to school.
問:( otherwise)詞性?和辨別它詞性的方法?

解答：

是副詞,用排除法,它不是介詞,動詞,形容詞