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
additional order
adjustment bonds
adjustment for parallax
adoption process
aggrandising
alternative division ring
Ampelopsis japonica
backrest angle
beta-decay synthesis
bigheartedness
blind-sided
caudron
cellular precipitation
cercospora tremae
chalcosphere
Circuit-mile
classification of objects
counter-plots
crystal impurity
dacus
degenderise
diesel starting fuel
differentiable manifold
domain of a fuzzy relation
etching structure
even-mass isotope
ex-gi
exchange law
fabric characteristics
faciostratotype
field divider
fixed-distance control
floating-point
full sized core
furaspor
gas tank valve
generalized data base management system
graduate schools
gymnologize
gyro display coupler
hemostasis by compression
hermiticity
honeymoon baby
isolated position
janua
John Hope Franklin
ladykind
left strike-slip fault
logical group
loop road
low resistance vaporizer
lysdexia
main gas container
minimal operator
modified uniform liability system
Monroeism
mourns
non-comparative element
nproes
order Ganoidei
original group
paccekabuddha
panda cars
parve
person responsible
phosphagenie
positional system
primary pollution
Promezhutochnyy, Mys
quenelle
re-expulsion
red cap
red-chalks
registration date/time
relation of schedule of consumer demand to indifference curve
repogles
rhaphiolepis indica hiiranensis
roosters
Sara Koyra
sayres
scipione
second tempering bin
section type mounting
serpent stars
spinorial
state-of-the-art facility
take sides with sb
temperature gap
the means of relay protection
theory of relation between heaven and mankind
there's a lot of it about
tixadil
traffic courts
transferred-electron diode
transient short-circuit
tyrindoxyl
undulated fibrous texture
valence angle
ventilator control
vibration-protected frame
virginia dare
Yser