众所周知，他曾在监狱里待过。

It's ___common ___knowledge that he spent time in jail.

众所周知，这种大众媒体的关注不可避免地影响家庭关系。

It is ___common ___knowledge that such attention in the mass-media inevitably tells on relationships in the family.

吸烟有害健康是众所周知的事情。

That smoking is harmful to health is ___common ___knowledge.