旅游需求产生的客观条件包括______。 A．足够的支付能力 B．旅游环境的改善 C

在315kVA以下的变压器低压侧计费的电力用户能量计量点应采用( )的无功电度表。

A．1.5级

B．2.0级

C．2.5级

D．3.0级

（2011年广东湛江，14题）请在横线上用恰当的化学用语表示：

（1）2个一氧化碳分子       ；

（2）钙离子       ；

（3）碳酸氢钠的化学式         。

建筑变形测量点可分为（）。

A.控制点与观测点

B.基准点与观测点

C.联系点与观测点

D.定向点与观测点

Today more and more people go to websites when looking for information. Although most readers go to websites for news and e-mail, a form of person-to-person news, or in the form of chatting, they also read books on the web. It’s called electronic book (e-book).

Electronic books could revolutionize reading, but people ought to consider their far-reaching impacts as well. "The e-book promises to cause a slow tragedy on life as we know it," Jason Ohler, professor of technology assessment, university of Alaska Southeast In Juneau, warned the World Future Society, Bethesda, Md. His assessment weighed the pros and cons (赞成和反对的理由) of e-book technology’s impact on social relationships, the environment, the economy, etc. Before you curl up (蜷曲) with an e-book, consider the disadvantages.

They increase eyestrain due to poor screen resolution, replace a relatively cheap commodity with a more expensive one, and displace workers in print-book production and traditional publishing. E-books make it easy to share data, thereby threatening copyright agreements and reducing compensation (补偿) of authors, as well as creating nonbiodegradable (不可生物降解) trash.

On the other hand, e-books save paper and trees, reduce the burden of the carrying and storing of printed books, promote self-sufficiency in learning, and make reading a collaborative experience online. They also create new jobs for writers and artists and encourage self-publishing. In final analysis, Ohler points out, e-books should gain society’s approval if a few conditions are met: make them biodegradable and recyclable, solve the problem of eye fatigue, be sure the "have-nots" get the technology, and support e-book training in schools and business.

What is e-books’ negative impact on social relationships().

A. They create new jobs only for writers.

B. Fewer and fewer people have access to new technology.

C. They may threaten some traditional trades.

D. They isolate people from one another.

狭义的假日旅游是指我国公民在（）、“五一”、“十一”等长假的旅游活动。