Good reasons exist for this.

译文：这样做有不少好处。

What else could it exist for?

不然它还能为什么存在？

This place does not exist for visitors.

没有游客知道这个地方的存在。

God says I exist for his glory (Isaiah 43:7).

上帝说我活着是为了他的荣耀（以赛亚书43:7）。

And maybe someone does exist for me somewhere.

也许某个人正在某个地方等待着我。

They can exist for many years as viable spores.

它们可在外界存活很多年。

Two mechanisms exist for removal of senescent RBC;

衰老的红细胞通过两种机制去除；

Some obvious difficulties already exist for Ahern.

对于埃亨来说，存在一些明显的疑难问题。

Outside of these they did not exist for one another.

此外,彼此之间便各不相干了.

Safe, effective vaccines also exist for human use.

已有供人类接种的安全、有效疫苗。