Those words are definitely offensive words. They are basically used to tell someone "I will do what I want to do. I don't care what you think." It is a way of lifting up oneself and putting down someone else.

Can't help but notice you have a lot of these type questions. How about trying a resource to help you with the right meaning and then you can try to use them rather than just asking for definitions. Anyway, this one means the thing is much deeper than what is already known or already done. Such as, "We've only scratched the surface of learning English." or "After working on this project for 3 days we've only scratched the surface."

The best thing to do is study some Business English words and phrases related to your field of trade. You can do that through a teacher if you know someone who teaches that kind of thing. (I think I am familiar with someone who can help you. : ) ) Something you should NOT do is assume you know the meaning and move on. That could lead to some serious problems when it comes to trade with foreign countries I am sure. You could perhaps even make some flash cards from business words and phrases you find online. Keep them with you and review them every chance you get. There is only one method to better your vocabulary. It takes time, practice and hard work.

Utterly lifeless. Here is a good source for finding the meanings of idioms. http://www.idiomdictionary.com/

A teenage girl

I found the picture below in a netizen's photo album on www.douban.com, and but the information about it was gone. 
In this picture there was a lovely teenage girl doing heavy labor work, carrying bricks with a handcart all the time. (try not to make the sentences too long.  stop when there is a place to stop.) and When the camera aimed at her face, she just gave us a big sunny smile. 
I just couldn't help to but love this teenage girl the first time when I saw her. She has an immensely strong character, combined with an (if the following word starts with a consonant "sound" use "a" not "an") a unique natural grace and an infectious optimism about life itself. 
It's a pity there is no other information about her, I really want to help her if she is in need. 
"Though I know little about you, your attitude toward life really encouraged me a lot. Best wishes for to you! Good girl." 

 

Hope this helps!   - Mr Mahaffey

"Of course! Everybody knows you. I just can't remember your name."

Read grammar books. In my experience English grammar is not the most exciting thing in the world. You should pay some money and obligate yourself to learn it. If you don't have the motivation of losing money, you probably won't be motivated enough to learn as much as you need to feel successful in knowing grammar.