The understanding of the cell is the key to comprehending biology because we are made of these cells, and biology (having the word "bio") means learning about our bodies and how amazingly they work.
It depends on the context, you could have either... I reached an understanding with Tommy not to fight any more. Tommy and I reached an understanding to stop fighting.
Potential employees and employers don't usaly know each other.What part of a job will you not have a clear understanding about at first?-the interaction and communication with an individuals...
Put yourself in there shoes. I'm not saying that you should picture your self with a mustache and stuff, but think how they would feel and when you text them try to learn stuff about them so than you...