时间:2019-01-22 作者:英语课 分类:英语时差8,16


英语课

Exploding Trees In a scene from Mary Shelley’s famous novel Frankenstein, one of the characters watches as a lightning bolt strikes a large oak tree. The tree is utterly 1 destroyed in a gigantic explosion. This might be good story-telling, but could such a thing really happen? Let’s find out. Lightning is nothing more than electricity: a LOT of electricity. A single bolt carries a peak current that’s ten thousand times what an average light bulb would use. All this electricity has only one aim: to travel between the clouds and the ground along the easiest possible route. Trees, which stick out of the ground like natural lightning rods, make this route a little bit easier. What happens when lightning strikes a tree depends in part on how long it’s been raining. Water is a much better electrical conductor than wood, and if the tree is thoroughly 2 wet, the bolt will travel along the water that soaks the tree’s bark. This might singe 3 the tree, but it probably won’t kill it, and it certainly won’t make it explode. If the bark is dry however, the next easiest path for the bolt is inside the tree, through the damp, sugary sap. A lightning bolt contains enough energy to bring a ton of water to the boil, so the sap is instantly vaporized. Like a pressure cooker with no safety valve, the tree will indeed explode, just like Mary Shelley reported. What’s more, Mary Shelley’s exploding oak tree is scientifically accurate in another way. Oak trees have particularly rough bark, and it takes rain longer to soak them than smooth-barked trees. This makes oaks especially vulnerable to lightning explosions.



adv.完全地,绝对地
  • Utterly devoted to the people,he gave his life in saving his patients.他忠于人民,把毕生精力用于挽救患者的生命。
  • I was utterly ravished by the way she smiled.她的微笑使我完全陶醉了。
adv.完全地,彻底地,十足地
  • The soil must be thoroughly turned over before planting.一定要先把土地深翻一遍再下种。
  • The soldiers have been thoroughly instructed in the care of their weapons.士兵们都系统地接受过保护武器的训练。
v.(轻微地)烧焦;烫焦;烤焦
  • If the iron is too hot you'll singe that nightdress.如果熨斗过热,你会把睡衣烫焦。
  • It is also important to singe knitted cloth to obtain a smooth surface.对针织物进行烧毛处理以获得光洁的表面也是很重要的。
学英语单词
achech
achromaticus
acupoints on lung channel of hand-Taiyin
adaptive decision
Amphilestidae
angle-resolved photoelectron spectroscopy
anglican catholics
arvf
asbestos concrete slab
ascotts
asmantas
bactrocera kandiensis drew et hancock
balleting
bareweight
betterment costs
bilharziasis
cancellable
car body
chain cylinder
chill area
common dandelion
Cooksonia
correct logon password
Corrigan's pulse
cryptocotylar
drink hard
dryopteris toyamae
eassel
east coast coal port
Ehrlich's hemoglobinemic bodies
eileen farrells
ensuest
entry velocity
eurotas (evrotas potamos)
feminine
fritillary flower
gene linkage map
genus sarcostemmas
gold export point
goldwells
guzzery
hagen-dazs
harees
horone
i like reading
immersion tank
indoctrine
inquorate
internal cooling grinding
Ipanema, R.
IXF
Japanese Committee for Radio Aids to Navigation
libbe
lichtenberg's figure
long range order parameter
luninyets (luninets)
mandibular muscles
maximum operation pressure
mechanical square
metric conversion
Mitreola pedicellata
mucilago tragacanthae
noncarbon
Normal brick
noureddine
on board securities
Oncorhynchus keta
out ot hand
overcutting jib
overexposed
pebbly sandstone
percentage ratio
Phormidium mucicola
photomedicine
placify
pony roughing stand of rolls
Port Antonio
quantitative defense
re-rated
reactor cell
receding cornice
reducingreduce tee
reflection rule
renin-angiotensin system (ras)
single-stage suspension
slag tap firing
soak up tax
Sorbostyl
spitfire
sympatholytic
tarasemide
test of smoothness
tildies
to send a cable
Waianae Mountains
wakemed
Walnut-oil
whip the devil round the stump
wound heart wood
write-only code
wydue
zincate