有两只昆虫先后飞过人的耳旁,飞行时,甲昆虫的翅膀每秒振动约200次,乙昆虫的翅膀

题型:选择题

问题:

有两只昆虫先后飞过人的耳旁,飞行时,甲昆虫的翅膀每秒振动约200次,乙昆虫的翅膀每秒振动约100次,则(  )

A.只能听到甲昆虫发出的声音

B.只能听到乙昆虫发出的声音

C.甲、乙两昆虫发出的声音都能听到

D.甲、乙两昆虫发出的声音都不能听到

考点:超声波和次声波的定义
题型:选择题

表观分布容积大小()

A.消除速度

B.吸收速度

C.血浆蛋白结合

D.半衰期

E.剂量

题型:选择题

读“亚洲地形图”,回答。

(1)亚洲地域十分辽阔,北部深入           圈以内,南部延伸到           以南,地跨               

                                                  三个温度带,东西跨经度达            ,时差达                  小时。

(2)亚洲东面和南面分别濒临           洋和           洋,水域广阔,因而东部和南部地区具有明显的             气候特征。

(3)填出图中下列地理事物的名称:

山脉:A                 ;B                   ;C                      

河流:D                 ;E                   ;F                       

高原:G                 ;H                  

平原:①                ;②                 

半岛:③                ;④                 ;⑤                      

岛屿:⑥                ;⑦                 ;⑧                      

(4)亚洲地势的特点是:                                            

(5)北极圈通过亚洲的                                                               三条大河。

(6)北回归线穿过亚洲的                                                    两个大半岛,穿过亚洲的                                      两条大河。

题型:选择题

胡粉散功效与作用

题型:选择题

阅读理解。

      At one time, computers were expected largely to remove the need for paper copies of

documents because they could be stored electronically. But for all the texts that are written,

stored and sent electronically, a lot of them are still ending up on paper.

      It is difficult to measure the quantity of paper used as a result of use of Internet-connected

computers, although just about anyone who works in an office can tell you that when e-mail is

introduced, the printers start working overtime. "I feel in my bones this revolution is causing

more trees to be cut down," says Ted Smith of the Earth Village Organization.

      Perhaps the best sign of how computer and Internet use pushes up demand for paper

comes from the high-tech industry itself, which sees printing as one of its most promising new

markets. Several Internet companies have been set up to help small businesses print quality

documents from a computer. Earlier this week Hewlett-Packard Co. announced a plan to

develop new technologies that will enable people to print even more so they can get a hard

copy of a business document, a medical record or just a one-line e-mail, even if they are

nowhere near a computer. As the company sees it, the more use of the Internet the greater

demand for printers.

     Does all this mean environmental concerns have been forgotten? Some activists suggest

people have been led to believe that a lot of dangers to the environment have gone away.

"I guess people believe that the problem is taken care of, because of recycling," said Kelly

Quirke, director of the Rainforest Action Network in San Francisco. Yet Quirke is hopeful

that high-tech may also prove helpful. He says printers that print on both sides are growing

in popularity. The action group has also found acceptable paper made from materials other

than wood, such as agricultural waste.

1.The growing demand for paper in recent years is largely due to ____.

A.the rapid development of small businesses  

B. the opening up of new markets

C. the printing of high quality copies          

D. the increased use of the Internet

2.  Environmentalists believe one possible way of dealing with the paper situation is ____.

A.to encourage printing more quality documents

B.to develop new printers using recycled paper

C.to find new materials for making paper

D.to plant more fast-growing trees

3.Hewlett-Packard Co. has decided to develop new technologies because ____.

A.people are concerned about the environment

B.printers in many offices are working overtime

C.small companies need more hard copies

D.they see a growing market for printers

4.What would be the best title for the text?

A.Computers and Printers                

B. E-mail and the Business World

C. Internet Revolution and Environment      

D. Modern Technology and New Markets

题型:选择题

在电子商务应用中,下面哪一种说法是错误的______。

A.证书上具有证书授权中心的数字签名

B.证书上列有证书拥有者的基本信息

C.证书上列有证书拥有者的公开密钥

D.证书上列有证书拥有者的秘密密钥

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