expose 

ex = out pose = postion 

I don’t want to expose my fears to anybody

BBC exposed the truth of the UK Cabinet corrpution （to show someone is bad and immoral in some way）

expose to=experience an idea or feeling

I exposed to  over a thousand new words all the night

turning point

I was by no means fluent In Chinese But it was a turning point from that night on.

apply myself = make the effort to do sth

I have to apply myself to learning the Science subject

come across

If you come across something or someone, you find them or meet them by chance.

when i come across a new person i can quickly to know where she is from by her accient

I perhaps come across him tomorrow

I‘ve never come across such an experience in my time.(经历过)