I ' ve found that cycles come closer together and more often during summer months and begin to become longer and farther apart during the winter months 我发现，发情期在夏天会更加频繁，两次发情期之间间隔的时间也更短；反之，在冬季，发情期就会变得更长，间隔的时间也会更长。
In primitive societies adolescence if frequently a relatively short period of time , while in industrial societies with patterns of prolonged education coupled with laws against child labor , the period of adolescence is much longer and may include most of the second decade of one ' s life 在原始社会，青春期通常较短，然而，在现代工业社会，随着教育时期的延长以及反对童工法律的制定，青春期也变得更长了，甚至包括人10 - 2020岁的大部分时间。
