People are confused in their attempts to control malaria in Europe in the early 1900s, because scientists ______.
A．identified only one mosquito species instead of six species
B．thought only three mosquito species transmitted disease
C．thought there was only one mosquito species
D．did not know what species was being studied
第1题：
175 Quality control charts show a characteristic of the product or service against:
A. the specification limits
B. customer requirements
C. control limits based on three standard deviations in each direction
D. control limits based on six standard deviations in each direction
E. A and D only
第2题：
Millions of people are in danger of getting malaria because______.
A. some countries have not started a campaign against mosquitoes
B. new species of mosquitoes may survive today's sprays
C. malaria was once thought to be a very old evil of the world
D. present sprays are not as effective as people think
第3题：
Quality control charts show a characteristic of the product or service against:
A . the specification limits
B . customer requirements
C . control limits based on three standard deviations in each direction
D . control limits based on six standard deviations in each direction
E . A and D only
第4题：
CDC considered the outbreak of West Nile in 1999 as a consequence of
[A] the abolition of the mosquito-control programs.
[B ] the surviving mosquito-borne infections.
[C] the abuse of some $ 50 million in funds.
[D] its failure to conquer mosquito-borne diseases.
第5题：
Time was when biologists somewhat over worded the evidence that these creatures preserve the health of game by killing the physically weak,or that they prey only on “worthless species。
第6题：
"Hidden" Species May Be Surprisingly Common
Cryptic species animals that appear identical but are genetically quite distant—may be much more widespread than previously thought. The findings could have major implications in areas ranging from biodiversity estimates and wildlife management, to our understanding of infectious diseases and evolution.
Reports of cryptic species have increased dramatically over the past two decades with the advent of relatively inexpensive DNA sequencing technology. Markus Pfenninger and Klaus Schwenk, of the Goethe-Universitat, in Frankfurt, Germany, analyzed all known data on cryptic animal species and discovered that they are found in equal proportions throughout all major branches of the animal kingdom and occur in equal numbers in all biogeographieal regions.
Scientists had previously speculated that cryptic species were predominantly found in insects and reptiles, and were more likely to occur in tropical rather than temperate regions. "Species that are seemingly widespread and abundant could in reality be many different cryptic species that have low populations and are highly endangered. " Says Pfenninger. Until the genetic information of all species in at least one taxon is thoroughly studied, no one will know just how many cryptic species exist. "It could be as high as 30%. " Pfenninger says.
"I'm extremely surprised by their results. " Says Alex Smith of the University of Guelph in Ontario, Canada. "It's a call to arms to keep doing the broad kind of genetic studies that we are doing. "
Sampling as many individuals as possible, scientists hope to complete work on all fish and birds in another 5 to 10 years. Once either of these taxonomic groups is completed, Pfenninger says researchers will be able to decide how many cryptic species exist throughout the animal kingdom.
Examples of cryptic species include the African elephant. A 2001 study found the elephants were actually two genetically distinct, non-interbreeding species, the African bush elephant and the African elephant. The species are currently listed as vulnerable and threatened, respectively, by the World Conservation Union (WCU).
The reclassifications are more than an academic exercise. They define populations that have evolved independently of each other and whose genetic differences can have significant consequences. In the early 1900s misidentification of mosquito species based on morphology confused attempts to control malaria in Europe. Ultimately, what was thought to be a single species was actually made up of six sibling species, only three of which transmitted the disease. "The basic unit in biology is always the species, and you have to know what you are dealing with. " Pfenninger says. Much previous research is now no longer used, he says, because it is not clear what species was being studied.
Which of the following about the significance of the research on cryptic species is NOT true?
A．The results of the research can help the development of many other research areas.
B．The results of the research can help the development of biodiversity estimates.
C．The results of the research can help our understanding of infectious disease evolution.
D．The results of the research can help our understanding of "survival of the fittest. "
第7题：
Passage One
Animals have different ways of protecting themselves against wintertime weather. Some animals grow heavy coats of fur or feathers, while others dig into the ground to find a warm wintertime home.
Some animals spend the winter in a deep sleep because by going to sleep they avoid the time of the year when food is scarce and the temperatures are low. Their sleep is known as hibernation.
There is much about hibernation that puzzles scientists. For example, they are wondering how hibernation came into being. Some scientists have explored the possibility that animals release a chemical that starts them hibernating.
One thing that scientists are certain about is that animals hibernate only when it is cold. Hibernation is a seasonal practice.
Some animals that fall into a wintertime sleep are not true hibernators because they spend only a part of the cold season asleep. Bears, for example, can easily be awakened from their winter nap. They are not true hibernators.
Sometimes it is difficult to determine whether a particular animal is a true hibernator. For example, some mice hibernate, but others do not. The same is true of bats. Some of them hibernate. Others do not.
36. Hibernation is a seasonal practice. This means it ______.
A. takes place only during a particular season
B. occurs only during the night
C. is a daily practice
D. only happens when a species becomes over-populated
第8题：
129 Quality control charts show a characteristic of the product or service against:
A. the specification limits.
B. customer requirements.
C. control limits based on three standard deviations in each direction.
D. control limits based on six standard deviations in each direction.
E. A and D only
第9题：
Why is it a problem if all the smaller fish species die?
A. It's not healthy for the environment.
B. People only like to catch big fish.
C. There are too many small fish.
D. The smaller fish can get lost in the lake.
第10题：
A、is
B、can be
C、are
D、have been