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
a saucy hat
aeolotropic crystal
air-cooled engine
amphipyra shryshana
amphitheatres
arrhythmokinesis
averted hemisphere
baiyun
branch leaf
bridge to bridge radio telephone
buccinator artery
calibercalibre
cannelured
capitals of peru
CD3AK
centralized grease automatic system
cesanite
classpaths
clockwise polarized wave
cold mixing method
comisserate
compulsive spender
copperfield r.
Counsel to the Crown
craw-craw
crawler tread belt excavator
delaps
delmontes
desalination by electrodialysis
discourse structure
dispatcher primitive
disseminated tuberculosis
divisor function
downward weight bias
driver's room
Dābeji
earned-incomes
Egyptianization
emery cone
Emstek
endoscopic removal of foreign body
enfevers
engineering fluid dynamics
exemption from tax as raw material
flip out
forced-convection oil cooling
fraction of saturation
gear firishing
gurgaon
half glazed partition
henad
hermetic enclosure header
immunologic island
isopropylcholestanes
job abort
kiteboard
ladder with platform
liborio
lumped statistics
magnetic action
malacanthids
megaflow mark
Micro-Thermy
minivet
Neuquinone
non-firm offer
nonmycorrhizal
oil-driven
optical sound track
padde
panamax ship
parabolic projector
perfusion injury
ponchielli
pondaung
premature labours
puccinia chrysanthemi
Pucciniaceae
pulse code modulation (pcm)
purling
rami articulares
Reversal Day
roller chain differential drive
screenerator
see better days
serogrouping
sinostemonine
slavica
small caliber piece
standifer
steelman language
strepticemia
strip annealing
tatches
time-sharing computer
tyre crown
unauthorized signature
useful lift
valve-seat insert
Venusian atmospheric layer
wasitline
West Dinājpur Dist.