I hope this is helpful,Hi,
Please let me the correct usage of...
Water under the bridge
'water under the bridge' is used to express the notion that whatever is being discussed is in the past and cannot be retrieved/is useless to worry about.
'When I was a child, my sister used to play mean tricks on me and I really hated her, but that's water under the bridge. Now we are really close friends.'
'She made millions of dollars and lived a luxurious lifestyle, but since she invested her money with Bernie Madoff, that's water under the bridge now.
Asleep at the wheel
Not paying attention to one's responsibilities/actions; 'spaced out'; 'sleepwalking' through one's daily life.
'Oh, my gosh! I forgot to bring my lunch to school again! I must have really been asleep at the wheel this morning.'
The reference is to a person who falls asleep while driving a car. The car continues to move forward, but not for long!
Bob is your uncle
This one I should really leave to a BrE speaker, but since it's one of my favorites, I'll give it a try.
It could be roughly translated as '...and there you are!' or even 'Voila!
"How do you get this container open?"
"Well, it's easy once you know how. First you press down on this little lever, and while pressing it, you flip this little thing here, wait two seconds and... (said quickly and cheerfully) Bob's your uncle! (meaning: 'there you are! It's open!')"