时间:2019-02-03 作者:英语课 分类:自然百科2012年


英语课

 A test run before attempting the fuel hungry and risky 1 trip to the planet below. 


 
Dreaming about Mars 2 and actually going there are two very different things. Mars may be our neighbour, but 35 million miles to the closest point is still a very long way from home. 
 
To put him on the surface of Mars, someone once joked there're only three issues: getting them there, keeping them alive while they are there and getting them back.
 
Our space age dreams of off-world colonies on the moon and Mars faded with the cancellation 3 of the Apollo Program and the last trip to the lunar surface in 1972. It didn't stop us from travelling, we simply switched from astronauts to lower cost, lower risk robotic explores. And when it comes to Mars, it's probably just as well. 
 
Getting to Mars is just unbelievably hard. We've learned that the hard way before certainly it gave to go back to the days before the rovers launch two third in the missions that they fall in the Mars and fail. They fail for all kinds of reasons: rockets that blew up and spacecraft that just vanished partly without a trace.
 
Five, four, three, two, one, engine start.. Lift off.
 
If you are ever lucky enough to book a flight on the first rocket to the red planet, you'd better be sure you've packed everything. The one-way trip is at least six months with no turning back if you've forgotten something. 
 
We can go to the moon and get back in a week. It takes about three years to go to Mars and come back. You have to carry your food, you have to recycle your breathing oxygen and your water. So it's a very, very major undertake. Within about three days, your earth looks very small. And within a week, it's just another star. And you suddenly are going to realize you are in very deep space and it can be a long time before you can go back.

adj.有风险的,冒险的
  • It may be risky but we will chance it anyhow.这可能有危险,但我们无论如何要冒一冒险。
  • He is well aware how risky this investment is.他心里对这项投资的风险十分清楚。
n.火星,战争
  • As of now we don't know much about Mars.目前我们对火星还知之甚少。
  • He contended that there must be life on Mars.他坚信火星上面一定有生物。
n.删除,取消
  • Heavy seas can cause cancellation of ferry services.海上风浪太大,可能须要取消渡轮服务。
  • Her cancellation of her trip to Paris upset our plan.她取消了巴黎之行打乱了我们的计划。
学英语单词
Abbott-35616
adviews
analytical column
Applecross, River
aromodendrene
arteriola et venula nasalis retin? inferior
artificial ag(e)ing treatment
blazers
body sense
brings up
bromotrifluoromethane
caixin
cast the shell
cellariole
chart aeronautical planning
chawners
colour phototelegraphy
contribution by paritcipants
cyclo
d.s.
demand obedience from sb
demotic
diffraction-limited lens
dihydroxyacctone
dipyridone
dyspneic
E O
EG Expert Group
electrical neutrality
enclosed ventilated
Epoxytrichothecenes
fines herbs
fixed elevator
folding fin
FORMAT statement
fruchtschiefer
galambos
gay bars
genus kinosternons
german short-haired pointers
glickenhaus
globe pepper
haloalkylated resin
hand-harvested
hop
i-iii
i-passed
i-wroht
IMP,imp
indoor staff
infrared phosphor
inline arrangement
insulated coupling
it's fair to say
Kaminokae
kraft process, kraft pulping
lever gun welding head
Libman's sign
logical specification
matched boards
meletre
mesobilin
middle-jiao resembling a fermentation tun
multivendor
myrtus communiss
nonlovers
obliquely zysomorphic
ojinaga
on one's heels
optical arrays
oral medication
osmon
personnel automated data system
piceo-
polynomial with nonnegative coefficient
problem reduction operator
raphaelle
reciprocal benefit
reserve trim tank
restorable system
roadside sprayer
saem
sallis
San Clemente
secondary attack
servo sensor
severe emotional disturbance
sheaf of regular functions
siccus
sieve
sneap
specified pressure
straight polarity electrode
sulfabrom
technology transfer
tetramorium amium
thoracic plane
timing relay
triadenum japonicum (bl.)mak.
two-quanta process
type foundry
waste heat recoverer