Hi everyone may someone help me with Chinese

#grammar

Do they sound natural? and mean the same thing? 1) It’s not so much what really happened as what they think happened that matters. 2) It's not so much about what actually happened, but rather about what they believe happened that matters.

Is there any website or dictionary that can help distinguish synonyms? Thank you for your help.

I have a problem distinguishing tackle，cope with，fix and solve . As far as I kown they can all followed by "a problem" but what's the difference? Could anyone help me please?

Who think he has a solution to Israeli-Palestinian conflict? share me your thought, please.

I have a problem distingushing essential and key. Essential problems，key words，what's the difference? Could anyone help me please?

I have a problem distinguishing among escalate ，increase ，improve and extend. Could anyone help me please?