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
aberrometry
abrotanum
adenomyositis
alaria crassifolia kjellm
allocation strategy module
anderton shearer-loader
Andorf
arab-berber
Artfjeld
ashiko
at the behest of
automatic routine
autophagolysosomes
ball platform scale
bankrupcies
Barkley, Lake
be straight with sb
bleachers
blockader
borrow memory control
cam shaft sprocket
canonical case
chloroserpidine
Choeropotamidae
cock body
cold-sensitive mutant
colors
common peppers
congenital cyst of sublingual gland
conical stiffener
contending passions
control requirement
cramoysen
dediploidization(buller 1941)
doors and windows
drive away at
dumbard
ekiti
fabrication platform
fatty acid activating enzyme
flouncer
flour milling
foundry mould
freestylers
generalized two-phase model
genus botrychiums
Goniothalamus yunnanensis
Hanover County
health-insurance
helicopter land ing gear
heterocarpy
homeware
indifference curve
interfering nuclear reaction
interradial piece
interrogation-inquiry
iron mts.
kalkilya
koevermans
lineae parasternalis
lost ground
magnify oneself against sb.
marching problem
moisture examining instrument
nautical meteorology
newly built
normal reactive force
occult tail
pabulums
Pelagonisou, Diavlos
plan bracing
polyaromatic amide (aramid) pulp reinforcement
put on side
quarantinable diseases
Quercus chingsiensis
rbol
rejiggering
Republic of Moldova
restriction fragment
roll tite hathcover
sctinography
semi-floating axle
serratamolide
share responsibility for
small horse hides
soup-spoon
station pressure
system programmed operator
television relay car
thain
the mode
three-statest
tit fucks
turntabling
uncommerciable
unpieces
veto vacuum unloading gear
virtual O device
voidableness
vriesea carinata
web of Penelope
yakalo