### Chinese: 流的并不只是血，其中包含脱落的子宫内膜。
### English: It wasn't just blood that was flowing, it contained the shed lining of the uterus.
### Errors: There is a minor error at "flow". There is a minor error at "contain". There is a major error at "the". There is a major error at "shed lining".

### Improved English: It’s not just blood, but also endometrium that fall off.