Underfrequency
降低了的频率, 最低的频率, 低于额定频率
🗣️ 情景例句
How many people will you be bringing?
你约了多少人来？
If you want knwledge, you must toil for it.
若要求知识，必须刻苦学习。
Six men have been trapped in a mine for seventeen hours.
6个人被困在矿井里已有17个小时了。