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
accesseries
acoustical filter
actual use
address resolution
air-cushion joint
allochthony coal
assembled epitope
bibliologies
blue screens
botrychium multifidums
butyl boron dihydroxide
calibration bar
chlorodiella crispipleopa
clinics
columbic compound
compressed nitrogen
contract drawing
crittercam
cross-compound double flow
cullet catcher
data center control
denim-clad
diffused-mesa transistor
divisional communication
earth-fixed reference
edomites
exposure factors
Falcataria
feeler stock
forbidden ground
fort fisher
forthirst
genocides
Gluborid
glycogen disease
ground return clutter
group hearing aid
gustatory modalities
Gyropidae
harbers earth current ammeter
heterocoelous
hilleberg
hydrotechnica
hyperfrequency
isle
ixodes granulatus
jewelweeds
kernel of homomorphism
kominuter
lemoxinol
LSONG
marine internal wave
maripas
Memory Stick
merbromine
mill shell
monitor TV under water
Monroe, Vaughn
mu-meson
myocardial reserve
omnius
orthotropic control
outgoing line circuit
paradoxical sleeps
Pimpinella caudata
planktonic foraminferas
plurilocular
positive-energy state
potential hydroenergy,potential hydroenergy resources
presumed dead
r-extinction
rastrate
reflective surplus value
research colloquium
restricted credit
reversible filter
ringing round
Riponite
root diameter of worm
semi-authoritarian
service action parts list
sitostane
spigot flameproof joint
standardization pulse
starfinder
stroke work index
sulfolysis
tabulated pedigree
take up block
the behavior
the stranger
through hole plating coating
trade down
triisopropyltin chloride
tringa flavipess
triosephosphate dehydrogenase
ultrafast neutron
universal yarn numbering balance
unpleasant woman
washing bear
zero element of a projective coordinate system