时间:2019-01-30 作者:英语课 分类:农业与发展


英语课

AGRICULTURE REPORT

August 6, 2002: Caviar from California


By George Grow



Broadcast:


This is the VOA Special English AGRICULTURE REPORT.


The American state of California is famous for its agriculture. Now, scientists are working to make California a
world leader in the production of caviar. Caviar is made from the eggs of the large fish called sturgeon. Caviar is
a popular and very costly 1 food in many parts of the world.



The University of California at Davis reports that California is already the world’
s
leading producer of white sturgeon. It says the state’s success is partly the result of
work by one of its professors.


Serge Doroshov (surge DOOR-uh -shof) joined the university’


s animal science department twenty-five years ago. He and his


team showed that it is possible to speed up the rate at which


sturgeon develop sexually 2. To do this, they successfully
changed the environment where the fish develop. They also used hormones 3 to influence the
production of eggs and male reproductive fluid 4.


Sturgeon and their ancestors are thought to have lived as long ago as two-hundred-million
years. That is long before the appearance of most modern fish. Sturgeon have long, thin
bodies covered with a series of bony plates. The head is also well protected with these hard
structures.


Sturgeon can live for more than one-hundred years. Some weigh more than four-hundred-fifty kilograms.
However, the fish develop slowly. Females 5 in the wild are not able to reproduce 6 until they are fifteen to twenty-
five years old.


Most sturgeon move from salt water into inland waterways when they are ready to reproduce. However, some
live permanently 7 in fresh waters.


Sturgeon were once common in North America. However, too much fishing, building projects and pollution have
greatly reduced their number. Today, Iran and Russia produce most of the world’s caviar from sturgeon. The
most valuable caviar comes from a kind of sturgeon called beluga (ba-LOO-ga).


Professor Doroshov showed that sturgeon could be raised in small bodies of water and large containers. He also
showed that the fish will eat food not found in their natural environment. He and other scientists are now
attempting to grow bigger, longer-living sturgeon that produce large amounts of caviar.


Professor Doroshov has also helped develop methods to raise other kinds of fish.


This VOA Special English AGRICULTURE REPORT was written by George Grow.



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adj.昂贵的,价值高的,豪华的
  • It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
  • This dictionary is very useful,only it is a bit costly.这本词典很有用,左不过贵了些。
adv.性别上地;按性别地;性欲地;两性之间地
  • to be sexually promiscuous 性生活淫乱
  • I was depressed,withdrawn and sexually frigid. 我郁郁寡欢,离群索居,没有什么性要求。 来自《简明英汉词典》
n.流体,液体;adj.流体的,流动的
  • Fluid includes both gasses and liquids.流体包括气体和液体。
  • The weather is fluid in summer.夏天天气多变。
n.雌性动物( female的名词复数 );女人
  • The male birds are more colourful than the females. 这种鸟雄性比雌性更加色彩艳丽。
  • The males in the herd protect the females and the young. 兽中的雄性动物保护雌性动物和幼崽。 来自《简明英汉词典》
v.生育,繁殖,复制,重做
  • The machine can reproduce a key in two minutes.这机器能在两分钟内复制一把钥匙。
  • The picture will reproduce well.这照片会印得很清楚。
adv.永恒地,永久地,固定不变地
  • The accident left him permanently scarred.那次事故给他留下了永久的伤疤。
  • The ship is now permanently moored on the Thames in London.该船现在永久地停泊在伦敦泰晤士河边。
学英语单词
abdominal organs
absorber precooling
aeschynomene americana americana
alter-ego
ammiol
anticorrosion alloy
Aranyaka
audio response terminal
betagalactosidase
billy cart
bleaberries
bludging
Buff-Throated
cadouk
capillary transport
cedarbirds
check figures
clearing time of fault
coastal front
coating damage
commutator micanite
constitutional thrombopathy
continentalize
cotranslational import
counterview
credit method
crus intermedium (diaphragmatis)
dogwalkers
double acting steam engine
e-z
espresso shops
false tripping
first-test
flat-pack-furniture
fourhorn sculpin
genus Hymenanthera
genus Palaquium
geometric density function
ghells
give appetite
glucolactase
graypate
grisham
haemolymph node
hellebrigenin
hobbyhorsical
impulse action
in order that
integration by parts
jih t'an
keratolysis plantare sulcatum
Khanpur
La Chapelle-Aubareil
Lebang
lever key
little fingers
long drinks
long-term planning of watersupply and demand
make a push for
minority group
model drive
mooers
moraes
Météren
obovate leaves
oistrakh
pearly bodies
Polyarnyy
positive after-potential
power manager
pressed-steel boot
purpuriparous
QMC, Q.M.C.
quantity of social labo(u)r consumption
receptitious
regrouped
regulating capacitor
REIT
Rheum undulatum
ro.
ruling and balancing accounts
show evidence of
signallers
slurry mixer
sonar optimum frequency
spits feathers
stability of atmosphere
start vector
statutory law
stochastic automata model
subnanometer
subordinal
tantalic chloride
teleirradiation
tolerators
Triobead-125
vapourizability
wayhouse
wear land
werdning-hoffmann syndrome
year of the woman
zygosome