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
abascar
acca
anti-hijacking vehicle
antiagricultural
axis of equilibrium
back ground current
bespurt
Bourdon pressure vacuum gauge
buzzi
canon regular
capacitive diaphragm
carbon-graphite impregnated with resin
change setting
chapitel
chaudhary
cheirokinesthesia
choreographer's role
Cimballa
cloverfield
continuous type asphalt mixer
contractorsplant
Corydalis bungeana
cover up
cryptography session key
Cullins earth
densification bridging
destructive delta
digestible protein
dirty poll
dispersion function
Doellingeria
elevon
Englishment
epigenomics
Erlistoun R.
fraenula
fraxinus griffithii clarke
genus Aulacorhyncus
GTP-binding proteins
hit lady
hustles
hybrid sliding-pressure operation
imbricatings
IRHC
ischiatic lymph glands
jailbroken
JTF HQ
Kenam, Tg.
little slick
luchaire
Luwembe
middlegames
migration inhibition test
monkhouses
monofil
moral-character
netsurfers
nodi lymphatici inguinales
noise-thermometer
non-corest
nonaffected
not readable
number of shares
opening bit
panelized construction
patten
pentamethoxyl red
per mile
peritoneotome
petalling
photo conductive lag
photo Joe
picatura de pito
premorphological stage
pressurizing system
primary workers
program content
propositional function
prototaxic
proxes
quick-changer
re-seller
rotating piston pump
say the final word
Shareable Content Object Reference Model
Sharīfah
ship synoptic code
shortened pulse
should-be cost review
smaldone
sponsor-level
stern frame casting
thioindoxyl
thowle
tomasko
universal-joint center ball pin
veneer planer
visibility
warehousing and storage margins
world wide tax jurisdiction
Wurtz's lactose litmus gelatin
Yugoslavian