It goes without saying that if someone has lung problems they should not smoke.

肺部有了问题就不该抽烟，这是不言而喻的。

It goes without saying that we should help a comrade in difficulty.

同志有困难当然要帮助。

It goes without saying that he never believe you.

不言而喻，他永远不会相信你。

It goes without saying that health is above wealth.

健康胜于财富这个道理是无需多说的。

It goes without saying that this message is very true.

毫无疑问，这里传递的信息是非常真实的。