The last one: “What can’t the brain function normally without?”

It should be “I’ve been too greedy. Look how I’ve ended up. I’ve lost everything..”

Literally it means to surrender to an opponent in a grappling sport, but metaphorically it means to give up or quit doing something that is difficult.

Self_ esteem

Lately I’ve been considering the concept of self-esteem. I’d been punishing myself with negative thoughts and also a lot of negative self- talk. For example, that I am not a good person and do not
deserve to live. I was comparing myself with others. I was always saying that everyone else is better than me. Ideas like these had controlled my mind,
especially during the years of my adolescence. However, I finally realized that having self-esteem and self-confidence are really important. When you have low self- esteem, you will not believe in your ability to be successful. I also realized that I should be nice to myself and care about my health and personal hygiene. I stopped comparing myself with others and henceforward I should only compare myself with my self of previous years and realize how much better I’m getting at achieving and improving.

If you help me with this I will be very grateful

4.Note how Prof. Derby expresses his appreciation of Dr. Rensky’s participation in the conference. Study other ways of expressing appreciation.

I appreciate your assistance/advice/frankness/criticism.
It’s very kind of you.
You are very helpful.
That’s/was the right thing to say/to do.
You’ve done a good job.
Good for you.
Well done.
That’s a good idea.
That’s it!

5.React to the following statements using expressions of Task 4:

 I’m going to change the notation. It’s confusing and inconsistent.- That’s it!
 I’ll type the text, you need not bother.- It’s very kind of you. 
 I have managed to do the job. It was not easy.- Good for you. 
 What do you think of my classification? I have worked on it for two years.- You’ve done a good job. 
 I said there was too little time left to spend it on arguing. Was I right?- That was the right thing to say.
 Could I help you with proof-reading? You look tired.- You are very helpful. 
 We are late. Let’s take a taxi.- That’s a good idea.
 I believe he should be told; no point in putting it off.- I appreciate your advice. 
 Let him have the most pay. He worked much more than any of us.- That’s the right thing to do.