above all – most importantly;
again and again – B2 – repeatedly;
ex: I’ve told you again and again not to do that.
the apple of discord – refers to a situation or object that causes conflict or contention, often between multiple parties. It originates from Greek mythology.
Achilles heel – a small problem or weakness in a person or system that can result in failure;
the apotheosis of someone – the act of making someone into a god;
at first glance – when first looking;
be fond of someone/something – to like someone or something very much;
ex: She’s one of my dearest friends and I’m very fond of her.
I’ve always been fond of flowers, so I’m delighted that the new house has a little garden.
(from) day to day – if something changes (from) day to day, it changes often;
due to something – because of something;