(1)
get over
= to return to your usual state of health,happiness,
etc. after an illness, a shock.
(It took me a week to get over my cold)
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(2)
get through
=*to be successful in an exam, etc. ** to reach the next stageof a competition.(player or team) *** to manege to do or complete somethinge.
(I'll get through the work in an hour)
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(3)
ge at
=*to reach something,**to get something.***to learn or find out something.
(He is too short to get at the book on the shelf)