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
1-anthrylamine
a catastrophic flood
accompanying symptoms
adipokines
almery
anti-tnf
arly
bar fibre
beer farts
berry-esseen theorem
beworries
Bezdan
bitstring pattern recognition
bone comb
boom derrick crane
bumfuzzle
cancer-tree
centrifuge moisture equivalent
chichele
come off
compensatory hypertrophy
Danube R.
demulsification number
dish wheel
draft estimate
dynamic society
ecmolin
electric residue
Eliot, George
extra-soft steel
fixed length logical operand
fluviomarine deposit
footing jackup drilling unit
forced block caving
formal sociology
gas constant universal
gold-sol test
islands of jersey
jansson
kandies
kerions
languring
leaky bucket
leap frog method
lloyd's common market secretariat
long drawn
magneto-mechanical effect
mainplane
maliky
mandibular notches
manual of operation
microhm
Narcopan
necroscleritis
nettop
non reflective mirror
nonvirgins
normal pentane
North Ryde
over-prescribe
palladate
pattern analysis
pcd
Phnom Liep
photojournalism
pittosporum moluccanum
push and towing arrangement
raphidivergens bacilliformis
respirocytes
rhatanies
Richmond Hill
rizq
robben i. (robbeneiland)
rotating bottle cleaning machine
sand blast barrel
Sandakan, Pelabuhan
Saskatchewanians
SCENOPINIDAE
seek a knot in a bulrush
sequential disk
set to
signal distrotion rate
sino-atrial bundle
soits
stadia transit
stibenyl
subovoid
system expandability
T.U.C.
tape recorder
the castle
thermoreceptive neuron
Three Mile Island
thrust fluctuation ratio
to break sb's back
toned paper
trubschachens
vertical direction counter
water turbogenerator
well-conned
welsh-mediums
zemana