时间:2018-12-27 作者:英语课 分类:英语时差8,16


英语课

Last time we talked about how astronauts eat and drink under weightless conditions in space.  


Today we'll cover the next question kids love to ask-how do astronauts go to the bathroom in space? It may sound silly, but it's really a good question, because weightlessness does make a visit to the latrine a tricky 1 proposition. 


Weightlessness poses two main problems in the bathroom. The first is that the astronaut could drift away from the bowl at any time. But there's a simple solution: they put on thigh 2 and foot restraints in order to go to the john! The second dilemma 3 is a bit more complicated. Here on earth, gravity assures that our waste falls downward, away from the body. But under weightless conditions, body waste has the disconcerting tendency to hover 4 close to wherever it exited the body. 


On the earliest space flights, astronauts had to tape a bag to their bodies to catch the waste. But that got pretty messy, so don't try it at home! Today, astronauts actually use flushing toilets-but the toilets flush with air, instead of water. First, the air flow draws the waste away from the body, then flushes it into storage tanks. All of the liquid waste from the spacecraft is stored together in a holding tank, which is periodically dumped overboard, where the liquid evaporates. Solid waste, on the other hand, goes into a container that's exposed to the vacuum of space. The vacuum completely dries out the solid waste, which is taken back to earth for disposal.  


 

1 tricky
adj.狡猾的,奸诈的;(工作等)棘手的,微妙的
  • I'm in a rather tricky position.Can you help me out?我的处境很棘手,你能帮我吗?
  • He avoided this tricky question and talked in generalities.他回避了这个非常微妙的问题,只做了个笼统的表述。
2 thigh
n.大腿;股骨
  • He is suffering from a strained thigh muscle.他的大腿肌肉拉伤了,疼得很。
  • The thigh bone is connected to the hip bone.股骨连着髋骨。
3 dilemma
n.困境,进退两难的局面
  • I am on the horns of a dilemma about the matter.这件事使我进退两难。
  • He was thrown into a dilemma.他陷入困境。
4 hover
vi.翱翔,盘旋;徘徊;彷徨,犹豫
  • You don't hover round the table.你不要围着桌子走来走去。
  • A plane is hover on our house.有一架飞机在我们的房子上盘旋。
学英语单词
acid rains
amphitheatre
arraignment
attentional focusing
bioerror
break-even graph
Burgaltay
cargo on deck
Chamaesium viridiflorum
check sth in
cleaner frame
closure of cleft palate by von Langenbeck operation
cold roll forming
color encoding unit
con anima
continuous cast materials
coporphyrin
credit memos
demerit rating
dihydroxy acetone
Dolgoprudny
Dowsby
ecma international
encyclopaedist
Error detection.
friendzone
geocentric apparent motion
germ theories
gradal
Guaniquilla
helicopter duster
hexagonal safety set screw
hot carrier diode
indium-foil detector
inexpugnably
information handing
international reserves
isoiridomyrmecine
jasperwares
Kelvin's circulation theorem
kinetic shift
lag element
leggywork
list of balances
litsea faberi hemal.
low - interest loan
loxogramme salicifolia
lunar satellite
lunule
make a mush of
Mangoag
marginal tick
Mbéti
mean normal gravity
meddyl
method of middle area
moisture percentage
money plants
negative reply
nyctaphonia
overall transfer function
oversailing courses
partially-filled transition matrix
phase of meditation
pincavage
post-mortem fault analysis
power van
preventer pin
problem-focused coping
pulse train generator
radio noise
reading stability
reagent glass
redeclaration
related parties
ryn
safeguard technology
sauce pot
Schmidt diet
schumaker
screwze
selenium sulfide
sheepbackrock
silicate bond
similitudinary bigamy
single point suspension spreader
slimline
Smitane
somnolites
sophorae flos
spondylus squamosus
state building
supraopticoneurohypophyseal
surrenderers
temperature control material
toolmakes
turek
two-bath developer
unwiving
weg
YCD
zebra-mussel