Cepheid variable stars are stars whose brightness changes at regular periods.造父变星是一种光线按规律周期发生变化的恒星.His first great discovery was made when he recognized a Cepheid variable star.他的首次重大发现产生于他认识了一颗造父变星的时候....
the artistic works of the period该时期的艺术品The play, whose style is rigidly formal, is typical of the period.这剧本是那个时期的典型作品, 风格拘谨刻板.To use the vernacular of the period, Peter was square.用那时的土话讲，彼得是个老古板。...
Fish populations assume highly localized distributions within each river.鱼群分布集中在每条河的某些区域.Those candies will the average distributions among those six children.那些糖果要在那六个儿童中间平均分配.Probability distributions are classified as...
That one mistake was his undoing.他一失足即成千古恨。The new president spent the first year undoing the work of his predecessor.新总统用了第一年的时间来收拾前任总统留下的摊子。His lack of experience may prove to be his undoing.他缺乏经验可能会最终导致他的失败。She has in...