Couple of things mean a couple, i.e. two. Not three (that would be ‘a few things’), not four, just two.
Such as and like are not inter-changeable. Like is used when implying a comparison. For example: Brave like a lion.
Such as is used when giving examples: Animals such as lions, tigers and other felines…
It’s never revert back. Revert itself means to ‘get back’. So you will revert to the e-mail.
Now can we all behave like 10 years of education got us somewhere? Thank you.