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
abortive zone
absolute dosimetry
Alficetyn
alloy diffused transistor
alloy-junction photocell
an underworld gang
arithmetical average head
at their fingertips
bare hand working
Bassila
be straitened for
beater head
beershops
bogo-sort
bomerang
cable tension
call names
cascaded drain
centralgol
circumflects
colopodacus parallelus
cover of a set
dielectric dry test
disablist, disableist, disable-ist
disfigurative
electroerosion machining
enjoy rights
exeception list
farm trust account
favourablest
fax-emails
final evaporator
finitary
fireless cooker
forced-steering radial truck
foxbrush
granulosity
grilling
ileus verminosus
intermittent failure
international trade and commerce
international war crimes tribunal
kaiseki
Kallavesi
keyboard clear push switch
kiloradian
kimball
kirgizias
laboratory effects
lead(ii) acetate
listen-before-talk
mandelbrots
mandibular bones
mean flow time
mechain
mechanics of vibration
mercury vapour
museum of anthropology
mutually disjoint family
non-coherent scattering
over-irrigation
overlock
oxidation bleaching
packing die
peroxids
piccolo
pitfighters
productive force economics
pseudokettle
re-engineering/restructuring
renal retinopathy
repairable data base
resistanc wire
revet
revolvements
Rhododendron pachysanthum
ring statistics
rubber bearings
rvflectionpolariscope
sandwich molding
Save As
sedentary
silver mirror
slipperworts
slipping up
sodium tetraarsenite
sophisticated electronics
stanols
stereoscopic viewing instrument
Stradella
submania
surmark
Talzaza
thermal reforming
tip table
total coefficient of correlation
trace metal(s)
transporter bridges
trentonian series
vision quests
w.a
welner