the existence of other galaxies.

其他星系的存在。

Public worries about accidents are threatening the very existence of the nuclear power industry.

公众对事故的担心正威胁着核能工业的生存。

The Congress of People's Deputies voted itself out of existence.

（苏联）人民代表大会投票终结了自身的存在。

You may be stuck with a miserable existence for the rest of your life.

你的余生可能过得很悲惨。