首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Initial voyages into space introduced questions scientists had never before considered. Could an astronaut swallow food in zero
Initial voyages into space introduced questions scientists had never before considered. Could an astronaut swallow food in zero
admin
2013-05-29
36
问题
Initial voyages into space introduced questions scientists had never before considered. Could an astronaut swallow food in zero gravity? To keep things simple, astronauts on the Project Mercury ate foods squeezed out of tubes. It was like serving them baby food in a toothpaste container.
But these early tube meals were flavorless, and astronauts dropped too many pounds. "We know that astronauts have lost weight in every American and Russian manned flight," wrote NASA scientists Malcolm Smith in 1969. "We don’t know why." Feeding people in space was not as easy as it looked.
Floating around in space isn’t as relaxing as it might sound. Astronauts expend a lot of energy and endure extreme stresses on their bodies. Their dietary requirements are therefore different from those of their gravity-bound counterparts on Earth. For example, they need extra calcium to compensate for bone loss. ’A low-salt diet helps slow the process, but there are no refrigerators in space, and salt is often used to help preserve foods," says Vickie Kloeris of NASA. "We have to be very careful of that."
By the Apollo missions, NASA had developed a nutritionally balanced menu with a wide variety of options. Of course, all the items were freeze-dried or heat- treated to kill bacteria, and they didn’t look like regular food.
Today, the most elaborate outer-space meals are consumed in the International Space Station (ISS), where astronauts enjoy everything from steak to chocolate cake. The ISS is a joint venture between the U.S. and Russia, and diplomatic guidelines dictate the percentage of food an astronaut must eat from each country. NASA’s food laboratory has 185 different menu items, Russia offers around 100, and when Japan sent up its first crew member in 2008, about 30 dishes came with him. Due to dietary restrictions and storage issues, astronauts still can’t eat whatever they want whenever they feel like it.
In 2008, NASA astronaut and ISS crew member Sandra Magnus became the first person to try to cook a meal in space. It took her over an hour to cook onions and garlic in the space station’s food warmer, but she managed to create a truly delicious dish: grilled tuna (金枪鱼) in a lemon-garlic-ginger sauce---eaten from a bag, of course.
According to Vickie Kloeris, serving a low-salt diet in space ______.
选项
A、is easier said than done
B、is not absolutely necessary
C、has worked as expected
D、will be the future trend
答案
A
解析
转载请注明原文地址:https://kaotiyun.com/show/jOTO777K
0
研究生英语学位课统考(GET)
相关试题推荐
ThedevelopmentandwidespreaduseofcomputertechnologyandtheInternethavetransformedhowwecommunicate,howwecommunica
HumanCloningTheapplicationsofcloningasweenvisionarenotnightmarishandinhumane,butwillimprovetheoverallqual
Doeshappinessfavorthoseofaparticularage,sex,orincomelevel?Socialscientistshaveexplodedsomemythsaboutwho’s
Some23millionadditionalU.S.residentsareexpectedtobecomemoreregularusersoftheU.S.healthcaresysteminthenext
Agreatdealofattentionisbeingpaidtodaytotheso-calleddigitaldivide—thedivisionoftheworldintotheinfo(informatio
TheUnitedNationsdeclaredlastFridaythatSomalia’sfamineisover.Buttheofficialdeclarationmeanslittletothemillions
Ithasbeenarguedthatwhereschoolsbecomebureaucratized,theybecomeboundupwiththetechniquesandimplementationofthe
Ithasbeenarguedthatwhereschoolsbecomebureaucratized,theybecomeboundupwiththetechniquesandimplementationofthe
Hisproductiontechniquesareelaborateandnearlegendary,buteveniftheycouldbe______,itwouldn’tbethesameforanyoth
Therearevariouswaysinwhichindividualeconomicunitscaninteractwithoneanother.Threebasicwaysmaybedescribedasth
随机试题
法洛四联症患儿突然昏厥、青紫加重的原因是
已满14周岁不满16周岁的人实施下列()行为应当承担刑事责任
下列评价指标中不属于盈利能力分析的是()。
下列各项中,属于对应付债券期末余额是否存在而进行审查的是()。
固定资产,是指企业为生产产产品、提供劳务、出租或者经营管理而持有的、使用时间超过12个月的非货币性资产。()
如果规模报酬不变,单位时间里增加了10%的劳动使用量,但保持资本量不变,则产出将()。
在非洲,握手时如果握得有气无力,被称为是“礼貌不周”,___________,毫无诚心。他们认为,用力的程度跟对方好意的程度是成正比的,最好握得手都感到麻木叫痛。填入画横线部分最恰当的一项是()。
试通过分析北京人的体质特征,说明“劳动创造了人本身”是科学真理。
为北方民族大融合做出杰出贡献的政治家是()。
(2001年)设随机变量X和Y的联合分布是正方形G={(x,y)|1≤x≤3,1≤y≤3}上的均匀分布,试求随机变量U=|X-Y|的概率密度p(u)。
最新回复
(
0
)