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
air army
air removal jet
aluminium foil backing paper
amplidyne servomechanism
ancient lights
apar-
Arianise
Arklitten
ascogone
atresia of external auditory canal
beaker in tall form
betrayer of the nation
biologic valence
bridge-and-tunnel
bronze screw hook
bus available pulse
CABG
cainell bone
Calef.
cargo spotter
casinder
cedrine
cephalic-medullar angle
Chinese Society of Naval Architecture and Marine Engineering
ciliary flame
construction design
cronartium quercuum
deduction for time lost
depth regulating device
derail accident
directly surveillanced subsection
display of interest
double-press process
elastic deformation pressure elements
extreme of fortune
faux hawks
Fenformin
filtering operation
fruit and bread pudding
heat cycle effect
high-mountain disease
Holzlar
intermediate range missile
international organization
jib-hank
key wall
labile sandstone
main shock strut
malacanthus latovittatus
mean transmission loss
NAMEDCEN
nucleobistone
ocoee
ordinary drawing
oriocrystal
para-substituents
Passarge
permanent kidney
photo current
photodensitometer
piloting district
PITTS
poignances
pre-preg
preorbital bone
prerecordings
program gain
proinflammmatory
Protoarticulatae
puopulsion system clutch
pustular dermatosis
Redo what was undone
reflection external form
reform and opening - up
reinduce
research fields
Rhodiola prainii
Rönneå
shuttering
silver reductor
skin pigmentation
skyphoi
somport
spinal subarachnoid space scanning
sprightliest
Sta.
Streptococcus viridans
subchoroidal expulsive hemorrhage
suspended-frame weir
systme
testing laboratory
thermels
toast list
treakle
tuck elastic webbing
turn on delay
turn-wrest plow
unlevied
user volume
vinyl guaiacol
wu t'u
zip-liners