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
adapted soil
antiphase boundary
apiocerids
ashtonite (mordenite)
athrogenic
bankruptcy rules
brachymeria lasus
capillary hyperpermeability
cargo line
check department
chicken run
chocka
clockwise turn
coherent-pulse radar
coking arch
concours
contact slide method
croisades
cuica
cultural institutions
cylinder cushion
dental silver amalgam
differentiated acoustic impedance
discount on bills sold on condition of repurchase
Djangoa
dossas
double draining
dual recording
dumbbell molecule
El Guamache
emakimono
eusociality
folin solution
G. K. Chesterton
glycinemia
Greater Accra Reg.
hedgie
Hellenian
Hungarian Kuvasz
Ilya Ilich Metchnikov
immune serum reaction
impressario
ink slinger
insufficient demand
isonuatigenin
joint deformity
juices
juxtacortical
kah
Khokhropār
landscape work
learning pattern
liquid-drop model of the nucleus
machine retrieval
macro etching
Maddrell salt
Malan loess
maximal point
mountain ebony
Mymensingh District
Neumann's law
nondesign
nonradial streak
orb-web
palmster
paraexciton
peniel
period Of isometric relaxation
phalium flammiferum
pivots
precommissural fibers
process fieldbus
propose to
radices macrotomiae
radionym
random library
regular isotopic
respectabilize
reverse-current drier
roast
second-messenger
semivertagus alveolus
shearsusceptible
Sonnenburg's test
stannites
stationary dog
statoconium membrane
subcutaneous ingninal ring
suite driver
Tallulah Bankhead
technical factor
tectonic valley
tend towards
the breaststroke
transonic equation
trigger-guards
twist disclination
unipolitics
unpuffed
unteachable
uredo clemensiae
zinc-anode for protection