长沙城下水道“八大公沟”最早建于清代什么年间？

已知α为锐角，则m=sinα+cosα的值（　　）

A．m＞1

B．m=1

C．m＜1

D．m≥1

---Could you please sweep the floor?

---_____________. I have to do my homework.

A．Yes, sure.

B．Why not

C．Sorry, you can’t

D．Sorry, I can’t

在中国传统观念中，（）象征着喜庆、幸福、吉祥。

A、红色

B、橙色

C、绿色

D、黄色

In the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet.

In recent years, there has been a dramatic increase in the range of media used to (71) information. Initially, communication was limited to simple forms of (72) such as voice and paper. This century, however, has witnessed the introduction of a greater variety of media types such as the telephone and visual forms of media. In the latter part of the century, this trend has accelerated and there is now a wide range of media types available to convey information. These advances provide a great opportunity for new developments in a range of areas such as education and commerce. However, there are also a number of problems associated with the growth of (73) in society. In particular, there is a great danger of creating information (74) . This problem can be seen, for example, in business where executives are required to make decisions based on an ever increasing variety and volume of information. (75) problems are also occurring in areas such as government, health care and education.

（72）是（）

A.mode

B.ways

C.medium

D.media

凭证式国债面向社会公众发行，发行对象包括（）。

A.个人投资者

B.企事业单位

C.行政机关

D.社会团体