Clinical study on safety of labor analgesia with in halation of laughing gas .
笑气用于分娩镇痛的安全性的研究。
The shadow brandishing through the snowflake , sees the sun resemble the fireball dragging a tail , issues the slight halation , such as luna in pouring reflect on water , be quite confused and stupefied , clearly go out to go out .
Halation : this is the result of light passing through the light sensitive emulsion , then through the film base , and finally being reflected back from the other side of the film and re-exposing the emulsion , but in a different place from the original one .
