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
acceleration test
acephobia
agig
air space
alloxazin
alpha glucosidase
antenna lobe
antirailroad
Azerraf
barbatinic acid
Baryshnikov
bidding rules
Bisongu, L.
bladerunner
C Language standard
cabinet latch
california-berkeley
carminophil cell
chacarero
chiasma frequency
chinese lesser civet
chory
circuit bridge
clustered aggregate
coila
constraint domain
contextualizations
descant recorder
direct-sum topological space
divellicated
drytte
easy as winking
electromagnetic seed cleaner
engine generators
forge fan
foul fish
generic attribute
geo-stationary orbit
good old dayss
hemp family
hide up
hiller
impactings
Institute of Navigation and Electronic Engineering
interest on current debt
iodine nuclide composition
irritable uterus
Kakindu
kampots
koettite
laminae cribrosa
laying in
leptostracans
lithosis
logical subnet
luragoes
magical realism
Minkowski coordinate system
noil yarn
non-participating
non-segregated
Norepirenamine
norflexes
notching relay
nystafungin
Phacelocarpus
plenicorn
precipitation particle
protopathic sensation
pseudocyclopiid
purple sandpiper
quench tower
Radauti
rate of occurrence of closing without proper command
recalculable
ring sticking test
rudderhole
Rule of Employment of Seamen
salming
saponated cresol
scriabins
self inflation
send date
shoka
short closing
single velocity stage
Strausstown
Streptococcus meningitidis
subvertising
sulphur hexafluoride
tamasi
tantalum sheet
Tensinyl
Terakeka
tetes-de-pont
trcrine
Trimethyl-1-pentene
wave-particle duality
wear mechanism
wet film hanger
write font