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
Anteuil
apagogic
Ascending Tops
associated company
blast finishing
business cycle duration
cardae tendinae
cock juice
commandantes
commodity projection
common subexpression elimination
conducive(to)
cultural warrior
desktop calculator
disengaging zero position
disproove
El Toboso
electrically-chargeds
electronic automatic message accounting
equalizer-analyzer combination
fathers-in-law
flow control device
fully associative cache
fuze head
generic programming
genus centrocercuss
Gorislav
gryzlov
Hemimandibulectomy
high elevation stacking area
holophrastic sentence
I-n-Akhmed
insufflation of Fallopian tube
intuitive music
irish peoples
iso-abnormal
jharkand
jigsaw listening
joint venture motor transportation enterprises
kettle chip
know your stuff
lerche
levi-civita
liquitab
living aquatic resources
load-strain diagram
lorell
magnetic quantum number
Margrām
meteorological aircraft
mondragon
mother shiptype operation
multitrace oscilloscope
NBP
noble metal
Nonproliferation Center
not claimed
not straight
numerical quantity
occupational intracavitary
offray
omeiense
opsomenorrhea
original game
pappose
periodic vortex
phenolic resin paint
plesiophthalmus uenoi
postnominals
risk framework
rissoilna materinsulae
samari
secret signalling
sequential logic network
series system of refining
Shaw hardness
shneid
short term culture
shsisms-s
Six-Day War
spare controller
stonecasts
sulfamethylpyridine
sulfur content in fuels
syngranitic deformation
t-day
technique system
tetartopyramid
the whole story
therapeutic diagnosis
There is none so blind as those who will not see.
three-light window
tishman
transformation of format
trim line
tuning fork type ammeter
twoperson
visaed passport
waveguide shutter
whale-huntings
working signaling link
X-ray absorption determination