词汇	极光回声
释义	极光回声 auroral echo
随便看	understand from understand fully understand his full worth understandible understandin understandin' understanding under-standing understanding abilities understanding ability understanding about understanding accounts receivable understanding analysis understanding and communication understanding and criticism understanding and experiencing understanding and explaining understanding and explanation understanding and grasping understanding and interpretation understanding and iron out differences understanding and practice understanding and recognition understanding and retaining Understanding and thinking