A project in ESL need your help!!

now i am administering a project in teaching Chinese sts pragmatic knowledge. yet i am in great need of the native speakers' help -- in providing the norm for the responses in the following 3 situations. would you kindly help me with this. thanks in advance.

these are used to elicit requestive expressions, and the situations are carefully designed from the most informal (more power, less social distance, low imposition) to formal (low power, more social distance, higher imposition). so would you please provide as more PROPER expressions as possible to guide me in teaching ES learners?

1.You are the director of a computer lab and have been working with an assistant, Joan, for two years. Joan has a duty to delete trash files in the computer every day. Today you wanted to install software into the computer. However, you found out that the trash files took too much space. It seems that Joan has not deleted trash files for several days. You ask Joan to delete them immediately.

2.You need to buy a new telephone card. But the store is quite far from where you live. You just got to know Miss Norris the day before yesterday, and you know she has a bike. You went to borrow the bike from her. what will you say?

3.You are revising your thesis, which is due in two weeks. You need five articles recently published on your topic, The Computer of the 21st Century. Although the library on campus does not have them, the library can ask other libraries in other states to send you the copies, which usually takes you one month to receive them. Since these five papers are very important and will add much weight to your thesis, you go to the head of Book Management Office (Miss. Anderson) to ask her to get these five articles in one week.

In the first place, English does not have a formal mode, as many Asian languages do. There are forms of English that are informal, but they all involve non-standard forms, slang or profanity, and are generally considered vulgar. An English speaker will address the queen of England with the same simple, polite sentences that he uses with his own mother.

1. Joan, please remember to delete your files.

2. May I borrow your bike?

3. I would appreciate your help very much.

In (American) English politeness has nothing to do with the speaker's status, eiither as employee and employer, parent and child, or businessman and street beggar. People will use polite forms of address if they are in an environment where it is valued, or if they were raised that way.

In any American office you may hear:

1. Joan, you idiot! If I have to tell you again to dump that trash, your butt is going to be out on the street!

2. You really look hot on that new bike of yours. You mind if I take it for a spin?

You get the idea.

Thank you so much for your help and suggestion. it makes me laugh to tears. :D

but i am puzzled by your third response. can it be so brief? i am expecting a response like "Miss. Anderson, i am a senior in this university...(more explanation). so i was wondering if you could help me with this and get these five articles in one week?"--this is what i will say. do you think it's alright?

or do you think these explanations boresome and unnecessary?

Dear Gxiang,
My advice in all of these situations (where a formal-style of speech is what you use in your native language) is to use simple, direct sentences with words expressing politeness. I know people who are offended by people who are too indirect, but nobody is offended by someone who says what he wants to say in a direct and polite manner.

As to your response to the librarian, I would make the initial request as simple as possible. This will show him that you respect how valuable his time is. If he is not able to grant your request, you could then add details to support your case.

Dear Mykwyner,
Your advice is really valuable to our project. Thank you again for your help.

Best regards.