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
024
aeronautical mathematics
altitude barrier
analogization
analytic fractorial
angle lap
antenna selection
apparent formation water resistivity
Auralgesic
axses
belisand
Berthelot equation
bombils
break in cross rates
BTBP1
cable flaw detector
casual-dress
centralized physical net settlement
clapper-boards
coefficient D
complotted
costively
crepin
cylinder wiper
day transmission
diaphonized
double deck
e-Taiwan
e-training
elementary antenna
energy flow diagrams
Equizole
fibre tensile strength
flight level
fructified
Geumodo
given room
hand hole cover
hand scudding
implate
independent errors
infrared crystals
initiating circuit
intravasations
inverted magetron
kouwenhoven
length of the underfeeding period
Malthusianize
mask opening
mechanical observation
mems inertial sensor
microphonic tube
migrating
mncigen granules
mountain and valley winds
move back and forth
muxed
neglecta macula
Neuropteridium
nihad
NIPOT
opsionosis
palladic cupraauride
perugi
phantasy life
Pitot head
police administration statistics
polyquinoxaline composite
polystichum deltodon(bak.)diels
positive heliotropism
prolactin releasing factor(PRF)
promutagen
receptive substance
salinity temperature depth (std)
Sanforised
scarifyings
self-confinement
semiquaver
seneca lakes
simplified block diagram
slip stopper
spherical harmonics function
spread spectrum signal
steye
storage network
submarginal resource
tadmore
tensiophone
thespians
three-hinged arch bridge
toolholder
top lander
trials by ordeal
trunk tree
unnested version
Use Ones Best Endeavors to Salve
valve-rocker bracket
vangoes
vinyl chloride rubber
wedge-shaped paper
wenchless
xcier