时间:2019-02-16 作者:英语课 分类:英语听力广播—Listening


英语课
【英文原文】
Sometimes the biggest finds are the smallest finds. Researchers examining a segment of siltstone taken from ground along the Beardmore glacier 1 in Antarctica found something unexpected. They found a fly.
Well, not exactly a fly. They found a fly fossil–it’s a segment of the exoskeleton, the protective shell, of a fly larva. While the larvae 2 are still growing, they are protected by a thin shell. And where there’s larval shell, there are flies. So what are flies doing in Antarctica? It’s much too cold there for flies. And the closest fly-friendly location, South America, is thousands of miles away.
Part of the answer is that the fly fossil is ancient–it was found with a number of other fossilized things that have been dated between three million and seventeen million years old. It’s possible that the fly lived during a period when sea levels were much lower there than they now are. Lower sea levels means wider continents –think of standing 3 on the edge of a beach and having the water pull back. And wider continents means its more likely that living things might travel across the gap.
Or maybe not. Maybe flies are much older than anyone thought. We know that what we now call Antarctica was once connected to both South America and Australia. But that was around eighty million years ago, and flies aren’t thought to be that old.
Whatever the answer is, something in our understanding of the continents, the seas, or fly evolution has to be fixed 4. That’s one of the best things about science–a really big change can come from the discovery of something really small.

n.冰川,冰河
  • The glacier calved a large iceberg.冰河崩解而形成一个大冰山。
  • The upper surface of glacier is riven by crevasses.冰川的上表面已裂成冰隙。
n.幼虫
  • Larvae are parasitic on sheep.幼虫寄生在绵羊的身上。
  • The larvae prey upon small aphids.这种幼虫以小蚜虫为食。
n.持续,地位;adj.永久的,不动的,直立的,不流动的
  • After the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
  • They're standing out against any change in the law.他们坚决反对对法律做任何修改。
adj.固定的,不变的,准备好的;(计算机)固定的
  • Have you two fixed on a date for the wedding yet?你们俩选定婚期了吗?
  • Once the aim is fixed,we should not change it arbitrarily.目标一旦确定,我们就不应该随意改变。
学英语单词
ACPP
agape
alkylene
alternative medicine
annular catwalk
appeasements
artemia salinas
barwood
be spoken for
beringe
biocrystal
cambium
Canadys
cathode disc
Chlodophen
co-occur
common lavenders
common situs picketing
continuous steelmaking process
contour follower
corrosion target
creped paper
crowsoap
cycle basis
Czechoslovaks
declaration of blockade
Den Bommel
digit area
electric blasting machine
electrocoat
elliptical aperture
entoplastic cells
flue sheet
fu wu
furnariidaes
get the better of sb
glenohunmeral
grass killer
gravity spiral conveyer
haick
heat and corrosion resistant steel
heresays
hi-technologies
high-fidelity loudspeaker
Hiron
huntingtower
immunosorbent assay
injection locking
intracardiac shunts
Kemetic
law of combining volumes of gases
linguistically
lissajous pattern
longitudinal strength
lumped parameter system
lutidine
macadamizing
machilaphis machili
make the acquaintance of sb.
makwetus
male heterogamy
Maloja(Maloggia)
micropogonias undulatuss
MVACT
notelovitz
oculata
on everyone's tongue
one-group pretest-posttest design
overrestore
photo plot
pin chain stenter
piombo
preist
preliminary site selection
pseudomola
PTHC
putour
rail-cambering machine
rate of rainall
Rayleigh scattering method
reblots
Remote Data Services
reverse osmosis method
rhinothix
safe ward
sbd
semi-pupa
shelf classification
Shūreghestān
slash dupe
speech processing system
static random access memory
Sulfetroni
summitor
tallow amine acetate
thio-oxydiphenylamine
traverse rib
unritual
unsolds
upper laser level
volupe
yield of groundwater