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
aerocab
angiospastic constitution
Appenweier
ascm-antiship capable missile
attenuation uniformity
axial stream
bath bombs
batoko palms
Birt
block mining system
buccal cavities
cerium-ankerite(codazzite)
chairborne
chromophotometry
coinmate
descripton
dichoptic
discernible signal
discussion experience
e-wave
electric diaphragm pump
electrocauterization of cervix
environment resistant connector
environmental management index
eulenspiegels
fall sown type
forearm free skin flap
foreseen
forward motions
frt.pd.
Fulgran
g.e
GBP (gain-band width product)
grading curve
ground layer
guncle
hecto-henry
ideal system
immediate family members
impacting block oil nozzle
infrared sensitive plate
L't
laminate board
lead climb
lithagogue infusion of amber
lividnesses
low-builts
lower cell limit
make no account of
Marshall R.
mean doing
membrum
mesodermalized
meum
mill fever
Modula
moon agreement
MRDD
msfc (marshall space filght center)
no home record
non contractual liability
on one's hunkers
particle bombardment
particulate material
pitsful
praiers
presumption of death
pumped robe
Rami interventriculares septales
reference effect
repeated shock
Robigalia
Rodionovka
rossett
screw-jack
selection wire
ship construction basin
sign picture character
somatopsychic
specific density
suspended hood
Talairach space
the four corners
Thiophysa
thorstein veblens
throttle controller
thunderbolt (thunderstone)
to play fast and loose
toreumatography
torquin' it
transition-fit
uginoxes
unabridged dictionary
under a 9-hours photoperiod
valleyforge
Vaux-Sous-Aubigny
vessel under sail
victory at sea
volontiers
voltage stabillizer
wind acceptance
zip it up and zip it out