下列不是城市生态系统特点的是（） A.人为性 B.不完整性 C.复杂性 D.丰富性

Celebrity endorsements

Despite the fact that companies believe celebrities had a lot of pull with regard to the buying trends of consumers,researches have discovered that this does not seem to be the case．British and Swiss researchers conducted a study showing that advertisements made by celebrities like David Beckham and Scarlett Johansson are not as effective as those by ordinary people．

In a sample of 298 students,researchers presented a magazine advertisement for a digital camera that was endorsed by a fictional student claiming the camera was“hot”and his “preferred choice”．The same advertisement was shown to other students，but with a difference：The camera was endorsed by a famous person in Germany．

While the students said that both advertisements were beneficial,the one made by the student topped the celebrity one if students aimed to impress others with their purchases.More than half of the students，who admitted purchasing products that would impress others，said they were influenced by the student’s advertisement．Only 20％ said the celebrity one would affect their buying decision．

Professor Brett Martin，of the University of Bath’s School of Management，explained that the findings could be used not only in Germany,but in other countries as well．“Our research questions whether celebrities are the best ways to sell products，”said Prof Martin．“Celebrities can be effective but we found that many people were more convinced by an endorsement from a fictional fellow students．This is because many people feel a need to keep up with the Jones when they buy．”

46．Some companies think the celebrities endorsement ____________．

A．is popular with the consumers

B．can pull all the consumers into the shops

C．can affect the consumers’ purchasing

D．is as effective as an endorsement from common people

47．Which of the following ads would be more effective to common consumers, according to the experiment?

A．An ad featuring lovely pandas．            B．An ad made by David Beckham．

C．An ad made by fictional common people．D．An ad with beautiful natural scenery．

48．The underlined words“the Jones”in the last paragragh refer to“____________ ”．

A．someone called Jones                                 B．common people

C．the Jones family                                        D．celebrities

49．We can imply from the passage that ____________．

A．celebrities cheat consumers in advertisement

B．the researchers here are against celebrity endorsement

C．the student’s ads are mole reliable than those made by celebrities

D．company needn’t spend so much money on celebrity endorsement

50．We can probably read the article in____________ ．

A．a local newspaper                         B．a science report

C．an academic journal                     D．a textbook

车轮轮缘磨损或崩裂将会造成起重机出轨的危险。（）

A、正确

B、错误

下列各组物质的性质由强到弱的顺序排列正确的是 [ ]

A．酸性：HClO₄＞H₃PO₄＞H₂SO₄          

B．氢化物稳定性：H₂S＞HF＞H₂O

C．碱性：NaOH＞Al(OH)₃＞Mg(OH)₂    

D．酸性：HI ＞HBr＞ HCl＞HF

以下说法不正确的是( )。

A．经济活动的外在性会导致市场失灵
B．政府主要通过产业结构政策提高垄断部门的资源配置效率
C．外部不经济可通过市场方式解决
D．交易双方信息不对称，会导致市场失灵

下列哪项不是收涩药的功效

A．敛汗

B．止泻

C．固精

D．止吐

E．止血