【正文】 semester my check was supposed to go directly into my bank account but there haven’t been any deposits.SecretaryThat’s odd.StudentYea, I thought graduate teaching a system for automatically put on the payroll at the beginning of the semester. SecretaryThey are. Let’s see did you plete all the forms for the payroll?StudentI filled in whatever they sent me, and I returned like the end of August.SecretaryHum, well, you definitely should have been paid by now. At least two pay periods have passed since thenStudentI asked the bank and they didn’t know anything. Who should I talk to about this, payroll?SecretaryI’m going to contact them for you. There was a problem in processing some of the graduate students’ payroll paper work.‘Cause their puter program crashed after all the information was processed. And some people’s information couldn’t be retrieved.StudentHum. But why didn’t any one let me know?SecretaryI don’t know how they work over there, ‘cause they couldn’t even figure out whose information was missing. And this isn’t the first time, seems like something like this happens every semester.StudentSo how do I find out if my information was lost?SecretaryI will contact them tomorrow morning to see if you’re in the system. But you’re probably not.StudentWhat then will let me to do?SecretarySorry but you will need to fill out those forms again and then I will fax them over the payroll office.StudentAnd then what… Well, what I really need to know is how long till I get the money, I’m already a month behind my bills and my tuitions due soon.SecretaryThat’ll get you into the system the same day they receive your paper works. So if you do that tomorrow, you’ll get paid next Friday.StudentThat’s a long time from now. Will that pay checking include all the money I am owed?SecretaryIt should. I will double check with the payroll department.StudentAnd another thing, Is there any way I could get paid sooner, I have been teaching all these weeks…SecretaryI know that’s not fair but I don’t think they can do anything。s certainly true that well no one likes getting calls at home from market researchers or people like that, but I will tell you something. Most customers have exact opposite reaction when they es to MBWA. Now, don39。s a good question, and well I don39。s…I think you could learn a lot by revising it.StudentYou mean, rewrite the whole thing? I really swamped. There’re deadlines wherever I turn and… and I don’t really know how much time I could give it.ProfessorWell, it is a busy time, with spring break ing up next week. It’s your call. But I think with all a little extra effort, you could really turn this into a fine essay.StudentNo… yeah…I mean, after I read your ments, I...I can see how it tries to do too much.ProfessorYeah. It’s just too ambitious for the scope of the assignment.StudentSo I should cut out the historical part?ProfessorYes. I would just stick to the topic. Anything unrelated to the use of nature EMITRY has no place in the paper. All that tangential material just distracted from the main argument. StudentYeah, I never know how much to include. You know…where to draw the line?ProfessorTell me about it! All writers struggled without one. But it’s something you can learn. That will bee more clear with practice. But I think if you just cut out the…emm…StudentThe stuff about history, but if I cut out those sections, won’t it be too short?ProfessorWell, better a short wellstructured paper than a long paper that poorly structured and wanders off topic.StudentSo all I have to do is to leave those sections?ProfessorWell, not so fast. After you cut out those sections, you’ll have to go back and revise the rest, to see how it all fits together. And of course, you’ll have to revise the introduction too, to accurately describe what you do in the body of the paper. But that shouldn’t be too difficult. Just remember to keep the discussion focused. Do you think you can get it to me by noon tomorrow?StudentWow…emm…I have so much…er…but I’ll try.ProfessorOK, good! Do try! But if you can’t, well, sure for after spring break, OK? Lecture 1NarratorListen to part of a lecture in a Biology Class.ProfessorAs we learn more about the DNA in human cells and how it controls the growth and development of cells, then maybe we can explain a very important observation, that when we try to grow most human cells in libratory, they seem programmed to divide only a certain number of times before they die. Now this differs with the type of cell. Some cells, like nerve cells, only divide seven to nine times in their total life. Others, like skin cells, will divide many, many more times. But finally the cells stop renewing themselves and they die. And in the cells of the human body itself, in the cells of every organ, of almost every type of tissues in the body, the same thing will happen eventually.OK, you know that all of persons’ genetic information is contained on very long pieces of DNA called Chromosomes. 46 of them are in the human cells that’s 23 pairs of these Chromosomes are of very lengths and sizes. Now if you look at this rough drawing of one of them, one Chromosome is about to divide into two. You see that it sort of looks like, well actually it’s much more plex than this but it reminds us a couple of springs linked together to coil up pieces of DNA. And if you stretch them out you will find they contain certain genes, certain sequences of DNA that help to determine how the cells of the body will develop. When researchers look really carefully at the DNA in Chromosomes though, they were amazed, we all were, to find that only a fraction of it, maybe 2030%, converts into meaningful genetic information. It’s incredible。ve ever heard, but it describes the process