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
a. palatina descendens
abomines
allotriophagia
apple blights
artificial monopoly
atypical antipsychotic drugs
ballism
bandha
bisabolane
bottom gating system
Buphedrin
cable in lead
Canejean
Carmella
centre of a pencil of hyperplanes
cheloid
chess-playing machine
cleithe
color correction
colourist
containment code
corbulid
cork oak
Corticoviridae
counter-inclined fault
cutter bearing
definitization
dialing system
dressing booth
Eastern Catholics
electrotinplate
esdud
Etacarlide
export wharf
extramedullary hemopoiesis of the skin
failure of apparatus
flat wire mill
floating head magnetic disk
Forbing
format track
four-cycle engine
geniuses
genus microgrammas
geological research vessel
Glandulae salivariae minores
guesstimated
half wave type
hamd
Heiser's treatment
hyperocclusion
inertious
ingrowing
isosorbide 5-mononitrate
KHD
know someone by name
layout design
littie
margaric acids
metallic resistor
method of ficitious loads
methyl acetate poisoning
micrococcus cumulatus tennis
monochrome illustration
netley
nonadjusted
nonoperation time
northwest computing association
notice of loading readiness
oedema gaseosum
operation continuous
Panstrongylus
partially incomplete protein
pencils
permanent distortion
petrostate
Phlebotomus chinensis
pinch-eyed
polynomial-valued
poorga
publicly traded fund
purchasing agent
repeal a decree
return rate of vehicle major repair
roll call principle
rotary selector switch thermometer
s africa
savanna(h)
sherin
shuttle type feed
squashlike
steam turbine by-pass system
stochastic kernel
SYN code
systematic failure
tissue culture vaccine
tonish
toxins of plant origin
unprogrammed
vibration damper plate
VMRS
whakapapa
Zaharias, Mildred Didrikson