时间:2018-12-26 作者:英语课 分类:美国英语听力80篇


英语课

[00:09.87]44) Edward Knipling

[00:15.52]A leading American research scientist died last month at his home in Virginia.

[00:22.88]Edward Knipling was ninety-one years old.

[00:26.75]Mister Knipling was a world famous expert in the study of insects.

[00:32.89]Most of his work was done for the Agricultural Research Service,

[00:38.30]the chief research agency of the United States Department of Agriculture.

[00:44.15]During his lifetime, Mister Knipling received many awards,

[00:49.97]including the National Medal of Science and the World Food Prize.

[00:55.38]Last year, Progressive Farmer magazine named him among twenty-one scientists

[01:03.06]who most influenced American agriculture in the past one hundred years.

[01:08.44]Mr Knipling developed effective ways to control insects without using harmful chemicals.

[01:17.43]His efforts resulted in the disappearance 1 of the wild screwworm population from North America.

[01:25.26]This has helped to prevent hundreds of millions of dollars in losses to farmers around the world.

[01:32.79]The screwworm fly lays its eggs in cuts in the skin of cows and other farm animals.

[01:41.75]When the young insects are born, they feed on the living tissue of the animals and cause serious wounds.

[01:50.63]Unless treated, an adult cow can die within a few days.

[01:56.09]Mr Knipling and another American researcher, Raymond Bushland, developed a method to stop the spread of the insects.

[02:07.40]They used radiation to make male screwworm flies unable to reproduce.

[02:14.69]Then they released the treated males to mate in the wild with fertile female flies.

[02:22.45]The eggs from the females could not become fertilized 2 and did not produce young screwworm flies.

[02:31.85]As a result, the number of the insects dropped sharply.

[02:37.34]This method is now used worldwide to kill other insects harmful to agriculture,such as Mediterranean 3 fruit flies.

[02:48.33]In Africa, the method is used to control the tsetse fly, which spreads sleeping sickness.

[02:56.07]Mr Knipling also helped develop the idea of using some kinds of insect enemies to control harmful insect populations.

[03:07.79]Some harmful insects are more easily treated with biological controls than with chemical ones.

[03:16.23]This idea has grown to include other methods that do not harm the environment



1 disappearance
n.消失,消散,失踪
  • He was hard put to it to explain her disappearance.他难以说明她为什么不见了。
  • Her disappearance gave rise to the wildest rumours.她失踪一事引起了各种流言蜚语。
2 Fertilized
v.施肥( fertilize的过去式和过去分词 )
  • The study of psychology has recently been widely cross-fertilized by new discoveries in genetics. 心理学研究最近从遗传学的新发现中受益匪浅。
  • Flowers are often fertilized by bees as they gather nectar. 花常在蜜蜂采蜜时受粉。
3 Mediterranean
adj.地中海的;地中海沿岸的
  • The houses are Mediterranean in character.这些房子都属地中海风格。
  • Gibraltar is the key to the Mediterranean.直布罗陀是地中海的要冲。
学英语单词
abjoule
aescine
airs cryogenic aerosol processor
ala of central lobule
amangkurat
ambulator
anomala loi
arietate
auger electron emission
becking
bendalloy
blunders into
bullbeggar
chain data address
CIE-C
committed effective dose equivalent
critical layer
cross colour
cylindrical chart
debit system
diffusion theory approximation
dunno.
end control
excelsior wrapper
falkow
flat tin
flower-piece
geake
Gemmatimonadetes
GM_nouns-and-prepositions
gymnosperm
hemalyke
heteroheptamers
hitchment
hoyt
indecent assault
intrasite communications
joachann
know how many beans make five
Koninckophyllum
kordell
La Trobe R.
Lauesymmetry
liquid mirror telescope
Lynenol
Marburg hemorrhagic fever
martyrs
masking tape
mating rate of virgin female meths
MCL level
meerbeke
mesodermic
minsk mazowiecki
mitochondrional
monargentic
Montreal River
municipally-owned
n.t.
operating hazard analysis
organorubidium
overall external dimension
paper wasp
pcoes
PCSA
pectinid
Pelham, Henry
physically impaired
picture demodulator
polianthes tuberosas
polycotyleden
pubococcygeal
quashed
radial-thrust force
reception facilities
recyclists
resource data subsystem
robert capa
sadi carnots
septate fiber tracheid
single-bed converter
soap bubble
Southeyville
spermatio-
spinal vein
sporidesmium magnibrachypus
squatting speed
St-Antonin
state contables
strainer vines
straw pick-up loader
subheads
suppressed output
surface-grinding
tatoin
time-line
transfer survey inmining district
troostites
V. I.
ventora
water line corrosion
Who are you wating for
X-address