问题 单项选择题

下面是关于树和线性结构的描述:

线性结构存在惟一的没有前驱的 (18) ,树存在惟一的没有前驱的 (19) :线性结构存在惟一的没有后继的 (20) ,树存在多个没有后继的 (21) ;线性结构其余元素均存在 (22) ,树其余结点均存在 (23)

由此可见,由于线性结构是一个 (24) 结构,元素之间存在的是 (25) 的关系,而树是一个 (26) 结构,元素之间存在的是 (27) 的关系。

(23)处填()。

A.惟一的前驱元素和后继元素

B.惟一的前驱(双亲)结点和多个后继(孩子)结点

C.叶子

D.一对一

答案

参考答案:B

单项选择题
问答题

To get help, Internet addicts tired of their square-eyed, keyboard tapping ways need look no further than the Web for counseling. There is now an online counseling service at www. relate, org. nz for Internet obsessives. Just e-mail the details of your Internet-induced crisis and help comes direct to your inbox. (46)The new breed of cybertherapists see nothing strange about offering help through the very medium that is swallowing their clients’ free time and splitting their marriages.

Getting hooked on the Internet isn’t confined to a few computer nerds. It’s on the rise everywhere—and women are the most likely addicts. The old stereotypical addict was a young man who spent hours playing games, downloading software or reading messages on newsgroups. (47)Yet, the new image is of a young woman who fritters away hours e-mailing friends, buying books and CDs online, talking in chatrooms and looking for information for next year’s holiday.

Ingrid Parker, once a slave to Internet chatrooms, found her experiences so devastating that she wrote a book to help other addicts break the habit. (48) Her computer dream turned to nightmare when she sold up and moved to be with her cyberpal (who had just left his wife), only to be told a week later that the couple were getting back together. The heart-breaking turn of events gave her the motivation to control her addiction—and write the book Caught in the Web.

For Ingrid Parker, anyone who is married or in a sound relationship should not really be spending hours talking to someone else and ignoring their nearest and dearest. (49)While Parker provided her own therapy by putting her experiences down on paper, she recommends others take up the online counseling offer, or log off from the Worldwide Web gradually.

She said, "It’s like smoking. It’s not a good idea to suddenly go cold turkey. People often e mail me about the problem and I tell them to gradually wean themselves off and not to switch to a scheme where you pay per hour for online time. (50)If they break their resolution, all they end up with then is the same old problem plus money difficulties for the long hours they have spent logged in to the Internet. "

Of course, the Internet is definitely addictive but if you can keep it in control it has advantages, too. Using it can be a steep learning curve so it helps you become very quick at learning. Also there is a huge demand for people in the field of Information Technology (IT) and hours on the Internet are great training.

(47)Yet, the new image is of a young woman who fritters away hours e-mailing friends, buying books and CDs online, talking in chatrooms and looking for information for next year’s holiday.