Do not throw out the baby with the bath water.

切勿因小失大。

I am running the bath water.

我正在放洗澡水。

I am running the bath water.

我正在放沐浴水。

Throw the baby out with the bath water.

把洗澡水连同婴儿一起倒掉。

Let the bath water escape.

让洗澡水流掉。