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
Acronema xizangense
air-pressures
antihemophilic factors
Artezian
automatic white balance control
basic electric furnace steel
basidiomes
bean plant
bitbrace
cassic acid
caught between the devil and the deep blue sea
centrally-controlleds
clamshell mark
class Gasteropoda
classroom setting
clavis
close one's ears
cofinitetopology
complementary square
condensate storage
conductorships
core of rope
croton bark
cyancarbonic acid
devitalise
distributed tp
Ditscheid
drum brake
endorseth
erythroleukaemia
esgair
EVOO
family Ichneumonidae
fixed tooth
garde
glyceryl-phosphorylcholine
gypsum raw ore
hairy cell
heedly
hit a man who is down
Homburg hats
ice melting current
immediate subcommand
immunostained
infamation
insedent
inspection station
interlobular septum
Jordanian dinar
liquid phase cracking process
local disease
micromeria chamissoniss
middle temporal vein
moment-curve slope
montes veneris
mortgage contract
mould core
neighbourhood
neody
neonationalism
nongoal
Omsang-dong
orthodiagraph
Ouangolodougou
pasture-land
peradvertence
Petrivka
planarian
Plica longitudinalis duodeni
post-secular
product standard
pseudoanalytic
rapid washing
register-select multiplexer
revenue above the line
rightmost
saffroned
Saul teaux
second-cousin
sequential marriage
side sill
Simulium neavei
single strcture
smelite (kaolinite)
snowscene
some rights reserved
southwest china
spatial properties
specification of a sequence of flow objects
St-Nectaire
storm runoff forecasting
supercavitation propeller
Sycopsis salicifolia
thagards
Thuringen
tired-out
uncommunicable
unterwind
vum
woohs
work in pairs
xanthoma diabeticorum