18．Great white sharks，the world's largest predatory（食肉的）fish，eat three to four times more food than previously thought，an Australian study shows．
    The U．S．research from the 1980s estimated a meal of 30 kilograms could make a one-ton shark continue living for more than six weeks．
    That made assumptions that large sharks could survive long periods without eating．
    However，a University of Tasmania-led study published this week in Scientific Reports found that 30 kg was only enough for 12-15 days．
    Researchers tagged （给…附上标签）a dozen great white sharks at Neptune Islands off South Australia and calculated their metabolic（新陈代谢的）rate based on swimming speeds．They worked out how much energy the sharks burned and how much food they required．
"Their metabolic rate is faster than we assumed．"
    Jayson Semmens was the lead author on the study．He said，"They（U．S．researchers） picked a shark that probably wasn't working very hard at the time when they did it．At the time it was a new study．They did some metabolic work similar to us but on one shark．"
"The white sharks，which we tagged，are working pretty hard…they're coming up to some pretty high speed to catch the seals．"he said，"Their metabolic rate is much faster than what we had assumed．These animals are probably going to be feeding every day，rather than several weeks．"
    The research also sought to improve understanding of how sharks fit into the ocean ecosystem．
"We don't have a good handle on the population sizes of white sharks．We know that sharks in general are under pressure around the world from overfishing，"Semmens said，"Furthermore，they're long-lived，they reproduce late in their life and they produce a small number of babies．"
    Semmens said the effects of removing white sharks from the ocean were thus far more important than realized．"They're keeping under control a lot more animals than we thought，"he said．

51．The U．S．research made people believe thatD．
A．large sharks could live without eating meat
B．sharks gained several kilograms in six weeks
C．a one-ton shark needed to eat 30 kg every meal
D．large sharks could live without eating for several weeks
52．What is Semmens'attitude towards U．S．researchers'job？C
A．Uninterested
B．Surprised
C．Objective
D．Satisfied
53．The shades'metabolic rate calculated by the two research groups is different probablyD
A．they used different research methods
B．they studied sharks of different sizes
C．the sharks they used for research were of different species
D．the sharks they used for research swam at different speeds
54．What do you know about white sharks？A
A．They play an important role in ocean ecosystem．
B．They can produce a large number of babies
C．They swim more slowly than seals．
D．They live a short life．
55．The author's purpose of writing the text is most likely toD
A．entertain
B．persuade
C．describe
D．inform．

17．The new study shows that we spend more time using the mobile Internet than reading newspapers or magazines．According to the European Interactive Advertising Association （ELAA），the average European spends 4.8 hours reading newspapers and magazines but 1.6 hours more using the mobile Internet a week．
    The EIAA questioned 15，000 people in 15 European countries，looking at how people are using the Internet and its influence on their everyday lives．It has found that the mobile Internet is increasingly finding its way into the public awareness．Over 71 million Europeans now have Internet access on their mobiles phones．In the UK，10 million people now access the Internet through their mobile phones and spend 6.3 hours doing so in a week．
    Unsurprisingly younger generations in the UK are leading the way，with nearly half of the country's 16-to-24-year-olds and a quarter of 25-to-34-year-olds using the mobile Internet，spending 6.5 and 6.2 hours online each week．
   Entertainment plays a major role in our mobile Internet lives，with one in five British people using their phones for online games，a third listening to the online radio and 39 percent watching films，TV or other videos at least once a week．One third of those using an Internet phone said they received videos，images or other multimedia on their mobile，and 61 percent said they passed on contents they received．
    From a communication point of view，80 percent of those questioned agreed that the Internet had made it easier for them to stay in touch with friends and family．
    Alison Fennah，director of the EIAA，said the mobile Internet use had come to the point that marketers should be looking to develop strategies that connect with consumers more effectively．"Better devices as well as improved consumer motivation that start coming together in 2011 can make a great difference to extending the online experience．"Fennah said．

41．How long does a European spend on the mobile Internet per week according to the EIAA？B
A.6.2 hours．
B.6.4 hours．
C.4.8 hours．
D.1.6 hours．
42．What do the words"doing so"mean in Paragraph 2 refer to？D
A：Reading papers and magazines．
B．Playing computer games．
C．Watching films online．
D．Using the mobile Internet．
43．What do people mainly use the mobile Internet for？C
A．Communication．
B．Study．
C．Amusement．
D．Advertising．
44．It can be known from the passage thatD
A．more than half of the young people in the UK use the mobile Internet．
B．the Internet is the most effective way to stay in touch with friends and family．
C．the UK has the largest number of people who use the mobile Internet in Europe．
D．better devices and improved consumer motivation help extend the online experience．
45．The author wrote the passage to tell us．C
A．how to use mobile phones to surf the Internet
B．newspapers and magazines will disappear soon
C．mobile surfing now is more popular than reading
D．how the Internet influences our daily life．

16．--What do you think of your journey to Yunnan？
--Everything is very fantastic，especially its fresh air．It is pleasant___．（　　）

A．

breathed

B．

being breathed

C．

to be breathed

D．

to breathe

15．We have only twenty minutes left，so please get to the point and don′t say anything that isn't ____to our problem．（　　）

A．

relevant

B．

sensitive

C．

familiar

D．

similar

14．Lucy_____ writing her essay by 10：00 this morning．After that，she listened to music for a while．（　　）

A．

will finish

B．

finishes

C．

has finished

D．

had finished

13．----I feel nervous when taking an exam．
----_______ and you can do it well．（　　）

A．

Take it easy

B．

Take your time

C．

Good luck

D．

It's up to you

12．Some traditional exercises like jogging，swimming and climbing may help people stay           （　　）

A．

in place

B．

in order

C．

in fashion

D．

in shape

11．一What does the sign over there read？
一 No person            smoke or carry a lighted cigarette or pipe in this restaurant．（　　）

A．

will

B．

must

C．

need

D．

shall

10．Colours like green can            a sense of life and quietness to people．（　　）

A．

acquire

B．

convey

C．

investigate

D．

remark

9．          goes up must come down，and gasoline prices are coming down fast in some parts of America．（　　）

A．

What

B．

Where

C．

Which

D．

That