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
(african) aardvark
act of procedure
aerodrome capacity saturation
analyzer polaniscope
Awjilah
bank failures
bergalls
blend seasoning
blood formation organs
bone protuberance
buncos
bursic acid
by persistence
camp meetings
canal orifice
capsule separation
CCSL
cellular respirations
check-valve ball seat
chromel copel thermocouple
constant wake field
continuous movements
creatine index
cryogenic freezing
cupola brick
customizing mail
Davisson, Clinton Joseph
desmonique
desponsating
discrete state
doubie Master
doubly-coupled linear programming
extension tongs
february spicebush
fecp
financial specialist
gas bell
genus aralias
gongylonemiasis
holo-cellulose
hominis
horsetail
hydrocyclone classifier
hydrofoil theory
Hypohysis
i'v
illutation
ingirdle
intermediat vector
Irishise
Karlsdorf-Neuthard
karny
kw
ladder company
lamb fast-gaining
leather machine belting
lombardies
machairas
macrogenitosomia praecox
mondinoes
new Internet knowledge system
non-apologies
noncompetitional
on-load voltage ratio adjuster
outgoing inspection
plasma pump
plugged crib
portunal
preliminary softening treatment
Prevalite
priming reservoir
pythium arrhenomanes drechsler
railway classification
ramyfye
raster laser plotter
relatively perfect set
retrograde filling
robespierres
rocka
roll direction
rotten clause
rustproofing oil
scugs
simulated clock
social realism
stopping bleeding and absorbing clots
superadministrators
sweeping-net
Synsepalum
t'see
tiludronic acid
to and again
totem-animals
tyledoside
underwater demolition team
unknotted ball pair
us veal
wait sb.'s leisure
weap one's heart out
Wednesday I.
white copper (domeykite)
x-pattern