March is one of the peak periods for our business.
三月是我们公司业务最繁忙的时期之一。
《牛津词典》
2
Earth was already in one of its warm interglacial periods when we started burning fossil fuels.
当我们开始使用化石燃料时，地球已经处于温暖的间冰期之一。
3
There were actually two periods of rain and lake formation: the first one began about 37,000 years ago; and the second one dates from about 10,000 years ago.