套利交易是指交易者针对市场上两个相同或相关资产出现的合理价差同时进行买低卖高的交易。

Internet shopping is a new way of shopping. Nowadays, you can shop for just about anything from your armchair. All you need is a computer which is linked to the Internet. Shopping on the Internet is becoming increasingly popular. In the United States, people spent over US $2.5 billion on Internet shopping in 1998. This figure is expected to reach US $11 billion by the year 2004.

People can shop for a variety of products on the Internet. Physical products include items such as books, CDs, clothes and food. These types of products are the most common purchases through the Internet. You can also buy information products such as on-line news or magazine stories, or you can download computer software through the Internet. Services such as booking airline tickets, reserving hotels or renting cars are also available on the Internet. You can also go shopping on the Internet for entertainment services and take part in on-line games.

Internet shopping offers a number of benefits for the shopper. The most important advantage is convenience. You can shop when you like as the on-line shops are open 24 hours a day and you don’t have to queue with other shoppers at the checkout counters. Secondly, it is easy to find what you are looking for on the Internet. Even out-of-print books may be ordered on line. Finally, it is often cheaper to buy goods through the Internet, and you can tell the shop exactly what you want.

The main disadvantage of Internet shopping is that you cannot actually see the products you are buying or check their quality. Also, many people enjoy shopping in the city and miss the opportunity to talk to friends. Some people are worried about paying for goods using credit cards, so Internet companies are now finding ways to make on-line payment safe.

Internet shopping is sure to become more and more popular in the years ahead. It promises to change the way we buy all kinds of things—from tonight’s dinner to a new car.

The phrase "physical products" in the second paragraph means().

A. things that can be seen or felt

B. things useful for health care

C. things that help you keep fit

D. things connected with sports

计件薪酬制

校信通用户致电客服热线，反映不能接收到学生到离校的考勤信息的原因是（）。

A.告知用户正确刷卡进校的方法；排除因操作方法不当导致不能接收信息

B.客服台在后台查询该用户业务开通情况，如果该用户已取消业务，我们保留的只有学生卡的功能，家长不能收到短信，学校可以在后台查询学生到离校情况

C.客服台在后台查询该校考勤机运行监控信息；排除学校考勤机设备运行不正常导致不能接收信息。如属设备原因，由客服到校进行设备检修维护

D.远距离考勤的学生收不到考勤信息或者是间断性的接收到信息，这就是2.4G复合卡出现了物理损坏，采取换卡处理

诊断透壁心肌梗死最有价值的心电图特征是（）

A.宽而深的Q波

B.ST段抬高呈弓背向上型

C.T波倒置

D.ST段抬高呈弓背向下型

E.ST段下降

《煤矿防治水规定》施行的时间是（）。

A.2009.12.01

B.2009.01.01

C.2010.01.01

D.2010.10.01