2 sentences

1. 地球绕太阳公转的周期是一年。

   dì​qiú rào tài​yang gōng​zhuàn de zhōu​qī shì yī nián.

   The period of the Earth's revolution around the sun is one year.

   Source: Dong Chinese Dictionary

2. 由于压力过大，她的月经周期变得不规律。

   yóu​yú yā​lì guò dà, tā de yuè​jīng zhōu​qī biàn de bù guī​lǜ.

   Her menstrual cycle has become irregular due to excessive stress.

   Source: Dong Chinese Dictionary