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
adjustable blade propeller pump
afikoman
agamospore
air exchange fan
amount brought forward
Anopheles amictus
anshim (ansim)
As-Vs interval
ballistic motion
be driven back on
be-fore
beggin
birsses
BPAI
British ton
build canal
bytecodes
Casaraccio, Stagno di
clairaudients
Clematoclethra scandens
coal seam pitch
Cohn's liquid
contextual protection
counter-brave
crack back
cutoff rate of return
cyclo-oxygenases
data test set
debentures stock
determining factor of value
discharge fee
dust-core coil
Eschrichtius robustus
exponential wire
feat
fiees
flat layered pile
forebuilding
frequentations
genus cynoglossums
horizontal rewind
hot-bulb engine
Hutchinson's disease
IFM (intermediate flow mixer)
isothecium subdiversiforme formosanum
light leather liming
magical realists
matriliny
maximum wind (speed)
mckitterick
method of model balancing
Monino
myeloid-erythroid
negative contrast
nonoperating expenses
nose-diver
Ogata's method
over provisioning
parallel-thread
peristomial ovicell
phenyl-boron dihydroxide
Piedraia hortai
points in time
positive ray parabolas
pre-clean
pre-feminist
prefractured rock
progranulin
pseudo-feedback inhibition
radiohumeral joint
repulsers
roghtangled spherical triangle
rudder-propeller
sandow
sarcomatous goiter
sebae
seeny
Sergeyevskiy
ship-to master file
sigilless
skin erosion
slope gain
Socinus
sound pressure transducer
synchronous controller
taper on diameter
taza
the retainer
tincture Physick's
top roll balancing mechanism
Trojanów
Unseasoned Security
v. supraorbitalis
Vaux
veloured
velours gandin
venae thyroidea superior
versatilists
water-skiing
web color
work code
X-ray imaging telescope