A backflow of urine from the '.

尿液从尿管回流到肾。

Four required per backflow preventer.

每个防回流阀需要四个。

The happy blood is unable the backflow centripetal dirty.

幸福的血液无法回流向心脏。

Since then we installed a backflow valve so it was less this time.

自从那时起，我们安装了一个逆流阀，所以这次少了很多。

The backflow preventer must be installed upstream of the regulator.

防倒流装置必须安装在调节阀的上游位置。