时间:2019-01-26 作者:英语课 分类:英语听力文摘 English Digest


英语课

Why is it that you can’t put down hydrogen gas? If you had a big balloon full of hydrogen gas, like the first gondola 1 balloons pioneered in 18th-century France, you’d find that it rises in the air quite dramatically.



You know that a piece of wood will float in water, right?


Sure.


That’s because the wood is less dense 2 than the water. When you’re in a buoyant medium, having a lesser density than your surroundings means you’ll float. Something with greater density than water, like a stone, will sink.



Air also has the quality of buoyancy. Anything less dense than the air will rise, just like a piece of wood held underwater and then let go. Hydrogen gas is only about one fourteenth as dense as air. So up it goes!


In fact, it rises with such force that it can even haul up a huge balloon, with a gondola and riders!




为什么氢气总是会飘起来?如果你有一个充满氢气的大气球,就像18世纪法国飞行先去发明的吊篮热气球,你会发现热气球在空中飘得很高。



你知道一块木头能浮于水上,是吧?因为木头密度比水的密度小。当你所在的浮力介质密度小于周围,你就会飘起来。石头一类密度大于水的密度的就会下沉。



空气也有漂浮的特质。密度小于空气的就会漂浮,就像放在水下的木头会浮起来一样。



氢气的密度仅仅是空气密度的1/14,所以氢气能漂浮。而氢气上升的力量足以托起载客的吊篮热气球。



 



n.威尼斯的平底轻舟;飞船的吊船
  • The road is too narrow to allow the passage of gondola.这条街太窄大型货车不能通过。
  • I have a gondola here.我开来了一条平底船。
a.密集的,稠密的,浓密的;密度大的
  • The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。
  • The path was completely covered by the dense foliage. 小路被树叶厚厚地盖了一层。
学英语单词
agricultural compensation policy
AIDDU
amorphous semiconductor material
antidifferentiation
ATCT
automatic mathematical translator
avenacoside A
balance of payments credits and debits
base (line) tape
basic magnesite
bok choi
builddown
byte boundary alignment
Cadomin
cantabile
carties
circaseptan
claspeth
Clearstream
common control connection
cordwaining
cross infection
diced line
dislocation earthquake
dispatch rider
earwear
electricoscillator
electronic certificates authority
ex-model
fan beam antenna
forced-lubrication
fully occupied
Fumette
gamma-thorianite
gastricsins
genus Tringa
gleade
goldeners
GPO,G.P.O
hickcox
horse-head fiddles
hour norm
howlsom
hunterine
indirect liabilities
interest rate risk
international rules of zoological nomenclature
intralipid
keel drag
kopsanone
Le Blanc-Mesnil
licked clean
Lipha
Lolong
M damage
magnesium chloropalladate
miner's horn
mochizuki
mortar setting
nitzschia cocconeiformis
nose of chisel
oil leak
optical current sensor
Pars occlusa
plati
premotor cortex
projectonometer
pull out power
quadrature-axis sub-transient open-circuit time constant
Rajiv
reducing of frequency
refuge bay
reichensteiner
remarkedly
rheubarb
S.A.F.P. (shop assembled fabricated piece)
session-establishment request
shawlless
shunted meter
shuttlecock ferns
single shear single rivet joint
slaneys
spic
sporidiiferous
sports coat
standard weather meter
standard-frequency meter
stood in the way of
storage
Strood
studio ghibli
synovial folds.
TDD (timing data distributor)
tyroglyphuss
vegematic
wacom
waithman
weichert
Westerlo
yesod
yoshimoto
z-axis