[简答题]One of the really nice features about e-mails is that they allow us to send files as attachments to other users. This is a very good thing. If I’’m working with a colleague and want to send him an image file or a word file, I can do so very quickly and easily, without having to fax it to him. This saves on long distance bills and printing costs. It also, however, presents a problem, because attachments can take a long time to download. For those of us who pay by the hour for Internet service, unwanted attachments can be quite costly and time-consuming. I once had someone send me fifteen large image files, and it tied up my computer for 20 minutes just to download one of them. So, in short, if you’’re going to send an attachment, get permission first.

[简答题]One of the really nice features about e-mails is that they allow us to send files as attachments to other users. This is a very good thing. If I’’m working with a colleague and want to send him an image file or a word file, I can do so very quickly and easily, without having to fax it to him. This saves on long distance bills and printing costs. It also, however, presents a problem, because attachments can take a long time to download. For those of us who pay by the hour for Internet service, unwanted attachments can be quite costly and time-consuming. I once had someone send me fifteen large image files, and it tied up my computer for 20 minutes just to download one of them. So, in short, if you’’re going to send an attachment, get permission first.

[单项选择]Which one of the following statements about the t - distribution is TRUE（）
A. The t- distribution is the appropriate distribution to use when constructing confidence intervals based on large samples.
B. Compared to the normal distribution, the t -distribution is more peaked with more area under the tails.
C. The t - distribution approaches the standard normal distribution as the number of degrees of freedom becomes large.

[单项选择]

Telling Tales about People

One of the most common types of nonfiction, and one that many people enjoy reading, is stories about people’s lives. These stories fall into three general categories: autobiography, memoir, and biography.
An autobiography is the story of a person’s life written by himself or herself. Often it begins with the person’s earliest recollections and ends in the present. Autobiography writers may not be entirely objective in the way they present themselves. However, they offer the reader a good look at the way they are and what makes them that way. People as diverse as Benjamin Franklin and Helen Keller have written autobiographies. Other writers, such as James Joyce, have written thinly fictionalized accounts of their lives. These are not autobiographies, but they are very close to it.
Memoirs, strictly speaking, are autobiographical accounts that focus as much on the events of the times as on the li
A. want to present themselves in a good light
B. constantly compete with biography writers
C. have trouble remembering the good times
D. feel they have to make up details to make their books sell