短语词组用作形容词 (adj.)～+名词frequent caller 常客frequent changes 经常变换frequent feature 常见的特征frequent visitor 常客副词+～less frequent 不是很频繁very frequent 很频繁alarmingly frequent 惊人地频繁annoyingly frequent 多得令人心烦relatively frequent 较为频繁～+介词frequent for 频繁地做…短语 返回 frequented