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
aber vrach
acquitted of a charge
alla marcia
automatic guidance system
basic framework
basic rights and duties
beat to
benchlets
bent tail dog
black land
BRL-2039
Burnett's disinfecting Fluid
Campofranco
caperer
carriage-returns
Central Div.
Cerastes cornutus
computerized mill
coronal sulcus
crystal water
deep water
delay-action stage
deterration
dipterocarpus oleoresin
dobias
El Manzanillo
Euler-Maclaurin summation for-mula
EVDICT
exclusive-OR gate
exemplate
fanning effect
Finsler geometry
flush cutting
food hall
Fumigas
fundamental wave
groundwater level forecasting
Guatemalan
HGH
high lift placing
high-speed telegraph transmitter
hold somebody to ransom
hydrgen fluoride
incidence coefficient
interstitial velocity
iron dry
it is surprise that
juxtacentromeric
L-C
ledgy
lithiumion
long center conveyer
low-water degradation
makka
master meter
mulgrew
Myristica L.
national currency per US dollar
non committally
ocean gyre
Ossa metatarsalia
out-building
over and short account
Oxitropium
parnassia delavayi franch.
periodizao
phosphate rock uncalcined
plateroom
poly-p-phenylene
Poygan, L.
public minded
pulling to
quadratic critical state model
ramsbotham
Red I.
reedsman
retablo
retroactive contributions
rocker bar heating furnace
rough surfaced blade
sharp hypothesis
short-range investment
short-range structure
simple gear train
skullface
standard oxidizing potential
Stevenson Cr.
Sumerian writing
tabliture
testimonialising
tinded
transportal crane
ultrasonic CW spectrometer
visage
vizirial
weissia newcomeri
whiskeys on the rocks
wide film
within-year
wohe
woundeds