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
aminosiloxydiene
Arthur Holly Compton
Aruntas
avesaurs
bacterial exotoxin
basic angle tolerancing system
betanaphthol benzylamine
cellinsulate brick
chaperonless
chlamydomonadaceaes
chuck it
cichorigenin
ciculation-period of sap
congressions
conservatism principle
conversion of motion
core print
Couiza
de-Sunnification
double-furnace boiler
dougrays
dramatized
edge substitution
edward
electrical surface resistivity
electro forming
empty bobbin
enterprise termination registration
equilibrium slide valve
exophthalmo-inducing factor
family Turdidae
flocoumafen
fuel storage pool cooling system
gallicized
gas pipe
genus Tetraclinis
gregariously
hard-copy printer
hardness tester
heat controller
heterooligomerization
Hilda Doolittle
homogeneous enzyme-immunoassay
horizontal scan frequency
horizontal sextant angles method
hydraulic lift mining system
hydrotherapeutor
hydroxide.
impellingly
informaticss
inter-american development bank
left service court
long-term drift
Lyon, River
material limit
merchands
microallocation
microconvection
midle
mononucleosomal
mush-mouth
nose wheel steering tiller
osteochondral fracture of knee
output transformer
palaeographist
parallel hybrid electric vehicle
peromelus
photo-romance
pillheads
polypetalous corolla
prepubescent
processus frontonasalis
pull behind ram
redifferentiates
reel machine
Regent's Park
risk-led
ropewalks
Rutudiga
sample averaging
schedule rating
screwed around
shuttle embroidery machine
silkens
skim bar
social perception
sowter
spoke to
squatjar
sufficient notice
sunken vessel
synclinicolpate
tourist-industry
transport cross-section
Trubetchino
two-circuit receiver
Tyberton
ultra-militants
untrustly
usage pattern
wearisomeness
where you at