短語詞組短語decreasing g series 遞減級(jí)數(shù)infinite decreasing geometric series 無窮遞縮等比數(shù)列series of decreasing powers 降冪級(jí)數(shù);降序級(jí)數(shù)series of decreasing power [數(shù)]降冪級(jí)數(shù) 返回 decreasing series