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
accourage
action for deceit
approaching cutoff
batch out
bay mouth bar
beam spacing
betula leuteas
bonderizing process
calibration mark
calvescent
carbazotate
case involving alien
Cephalotrichium
cervical syndrome
christus
claydens
common-channel signalling
confluence step
construction firms
contraguided stern
copper oxide rectifier
cylindrical layer
dangerous goods mark
dative sickness
deadstarting
dikas
domotics
downdraught cooler
driving gear bush speedometer
ecarteur
ejaculatory
exegeted
family (care) leave
fertilizer pump
foot-hook
forcing down
Free-Nets
freight rebate system
fresh water zone
General Strike Clause in Gencon
genus Anomalopteryx
gilard & dubrul factor
guerard
gullwings
haematopoetic
heavy non-ferrous metals
helium gas turbine
hogeous
Hoghes printing telegraph
hydrosulfides
hyper igm syndrome
hypoxanthine-guanine phosphoribosyltransferase
isomexoticin
Kovač Planina
labiate calyx
late-life crisis
laux
law of conservation of linear momentum
low power level
McCormac's reflex
neocheiropteris phyllomanes ching
neolignan
Nitromonas
opistho-graphic
organization for embarkation
pachpadra (pachbhadra)
package-drying machine
petroseline
pollinated variety
polygonal support
praseodymium oxide
precision measuring technology
prisoner's base
Päinurme
rammist
ranchland
resilient shock absorbing suspension
roseatest
sarcogenic cell
secondary electron emission factor
sectaries
signy
slow-motion recorder
smooth chorion
social conditions
sole pan
spin ball
spratelloides gracilis
spurtle
ST_knowing-and-understanding_difficult-to-understand
steaming-out line
supervgas
tax-resident
tiltyard
Trachelium
tupped
twin deck vessel
type of construction type
uk brand
undistressed
willow bells
Zechlin