menstruation

名词

1. 1

   月经、行经、经期

   Many girls begin menstruation between the ages of ten and fifteen.

   许多女孩在十岁到十五岁之间开始有月经。

2. 2

   生理期、月经期间

   Mild cramps during menstruation are common and usually harmless.

   生理期出现轻微腹痛很常见，通常无害。