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 minefield
abbey-like
absidia spinosa azygospora
AC-DC-AC drive
access declaration
aniline black dyestuffs
anti-aging agent
approved account
Araripe, Chapada do
arm and arm
Azingo
Battle of Bull Run
birational mapping
bottletop
Cambrian explosion
Canterbury hammer
Chelex resin
chondrichthians
cistvaens
closed-loop recirculation system
complementary NOR gate
controlled security
data flow-oriented analysis method
definite-article
delias
dickthomssenite
disk shaving cutter
double arm kneading mixer
electrically operated rheostatk
elephantship
enhanced-modes
enucleate
epiphenomenalistic
fainlessly
fair-pleader
fairleads
finishing mill line
fluctuating of speed
gaudryceratid
give sb the (glad) eye
gulph
hardware independent
hextetrahedral
horizontal property
Hufeland's powder
Indoklon
initial calibration
inland BL
ircams
kicked-off
land width of the face
lateral or conglomerate diversification
launch release mechanism
letters of patent
library efficiency and effectiveness
London clearing banks
Machilus chuanchienensis
magnaneries
magnetites
Mezasulfamid
moonshiny
musculus sphincter ani internuss
neurogenic acroosteolysis
neurovirulent
noninterpretive
normoxid layer
northern sea robin
nursing homes
on every account
open-mouth impression
Ould
over drawing
pad dyeing
pahoechoe
pearlite critical cooling rate
penal system
penopubic
piggy-back anchor
precess-limited
public storage
purchase return and allowance journal
random-phase approximation
re-building
Regent diamond
right spherical triangle
scatch
securing ring
self-contained regulator
skin stretching needle inserting
sodium pentauranate
special data
startup sequence
supersonic inlet buzz
swimming hall
tacitness
tee-square
tomaino
tree planter
TYS
ultra-violet filter
viviparous fish
width constriction