阅读下面的文字,完成小题 浩瀚无垠的海洋似乎永远是不会干涸的。大海中的水是怎么来

题型:阅读理解与欣赏

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阅读下面的文字,完成小题

浩瀚无垠的海洋似乎永远是不会干涸的。大海中的水是怎么来的呢?

有学者认为,这些水是地球本身固有的。在地球形成之初,地球水就以蒸气的形式存在于炽热的地心中,或者以结构水、结晶水等形式存于地下岩石中。那时,地表的温度较高,大气层中以气体形式存在的水分也较多。地球在最初的5亿年,火山众多且活动频繁,大量的水蒸气及二氧化碳通过火山口喷发出来,冷却之后便渐渐形成河流、湖泊和海洋,即所谓的“初生水”。

为了寻求地球水的渊源,人们把目光投向了宇宙。科学家托维利提出的假说:地球上的水是太阳风的杰作。太阳风即太阳刮起的风,但它不是流动的空气,而是一种微粒流或带电质子流。根据托维利的计算,从地球形成至今,地球已从太阳风中吸收了多达17亿吨的氢,若把这些氢和地球上的氧结合,就可产生153亿亿吨水。

科学家路易斯•弗兰克也提出一个新理论:地球上的水可能来自迄今为止还未观测到的由冰组成的小彗星。他在分析卫星图片时发现了一些黑色小斑点,而这些黑斑是高层大气中大量分子聚集而形成的气体水云。他认为,小黑斑现象是许多小彗星不断地把水从高层注人大气,形成彗星云团,而后化作雨降至地面。不久,在600多千米上空,他又发现了带状发光物,即含水破碎物留下的“尾流”。而这一高度又恰好是此类彗星可能徘徊的地带。1990年,一块冰体从天而降,落在中国江苏省无锡梅村乡。我国专家经潜心研究后认为,此冰块就是来自彗星。弗兰克理论还为一些未解之谜提供了解释。例如可能就是由大量的小彗星倾泻而下,造成地球气候剧变,才使恐龙及其他一些物种灭绝。1998年美国科学家打开了一块来自彗星的陨石,结果竟在里面发现了少量的盐水水泡!不久又发现另一块陨石里布满了奇怪的紫色晶体,这些晶体里竟然有水!

对于小彗星是否为地球带来过大量降水,科学家们正在不断地观察,不断地试验。

小题1:下列对所谓的“初生水”表述准确的一项是(   )

A.存在于炽热的地心中的水蒸气。

B.存于地下岩石中的结构水、结晶水。

C.大气层中以气体形式存在的水分。

D.由火山喷发的水蒸气冷却后形成的水。小题2:下列选项中,不能支持弗兰克理论的是(   )

A.地球上的水有可能来自由冰组成的小彗星。

B.在彗星可能徘徊的地带发现了含水破碎物留下的“尾流”。

C.经我国专家研究,落在中国无锡梅村乡的冰块来自彗星。

D.有的陨石里含有盐水水泡或含水的紫色晶体。小题3:根据原文提供的信息,下列推断不正确的一项是(   )

A.根据托维利假说,人类有可能利用太阳风获取更多的水。

B.根据弗兰克理论,人类有可能借助彗星云团进行人工降雨

C.对地球水源地研究,有助于预见地球气候还将发生剧变。

D.对地球水源的研究,有助于了解其他行星是否有水存在。

考点:现代文阅读
题型:阅读理解与欣赏

若正数a,b满足ab=a+b+8,则ab的最小值为______.

题型:阅读理解与欣赏

管理信息系统的综合结构中有一种是把同一管理层次上的若干相关职能综合起来形成的,这种结构称为

A.层次结构

B.总的综合结构

C.纵向综合结构

D.横向综合结构

题型:阅读理解与欣赏

Eating a diet high in processed food increases the risk of depression, research suggests. What's more, people who ate plenty of vegetables, fruit and fish actually had a lower risk of depression, the University College London team found.

Data on diet among 3,500 middle-aged civil servants were compared with their emotional state five years later, a British journal reported. They split the participants into two types of diet--those who ate a diet largely based on whole food,which includes lots of fruit, vegetables and fish,and those who ate a mainly processed food diet, such as sweetened desserts, fried food, processed meat,refined grains and high fat dairy products After accounting for factors such as gender, age, education, physical activity, smoking habits and chronic(慢性的) diseases, they found a significant difference in the future depression risk with the different diets.

Those who ate the most wholefood had a 26% lower risk of future depression than those who ate the least wholefood. By contrast, people with a diet high in processed food had a 58% higher risk of depression than those who ate a diet low in processed foods.

Study author Dr. Archana Singh Manoux pointed out there was a chance that the finding could be explained by lifestyle factor they had not accounted for. He also pointed in a paper that a Mediterranean diet was associated with a lower risk of depression, but the problem with that is if you live in Britain, the likelihood of you eating a Mediterranean diet is not very high.

Dr.Andrew McCulloeh, chief executive of the Mental Health Foundation, said, this study adds to an existing body of solid research that shows the strong links between what we eat and our mental health.

He added people's diets were becoming increasingly unhealthy. The UK population is consuming less nutritious, fresh produce and more saturated fats and sugars.

小题1:The text is mainly about         .

A.the increasingly unhealthy diet of the UK population

B.the link between processed food and depression

C.the relationship between physical and mental health

D.the emotional state of the British People小题2:What do we know about the participants?

A.They are of different ages from young to old.

B.They are from different walks of life.

C.They chose the diet they preferred.

D.Their state are also affected by other factors.小题3:What can we learn from what Dr. Archana Singh Manoux said?

A.It is difficult for most British people to have a Mediterranean diet.

B.The Mediterranean diet is the most healthy in the world.

C.Many studies have been done on the Mediterranean diet before.

D.The Mediterranean diet is not good for depression.小题4:Dr. Andrew McCulloch agrees that         .

A.our diets are closely related to our mental health

B.the present study needs more facts and other information

C.the UK population will become ill in the near future

D.more saturated fats and sugars should be taken in小题5:Why might the author have written this text?

A.To tell people what a healthy diet actually is.

B.To prove people’s diets are increasingly unhealthy.

C.To encourage people to cut down on processed food.

D.To introduce some experts on the research team.

题型:阅读理解与欣赏

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A.高压

B.较高压力

C.中等压力

D.低压

题型:阅读理解与欣赏

你作为项目经理,正在为西南某地方电信公司的一个远程机房监控项目工作,该项目要求在2008年5月30日前完成。由于地震的原因,你的项目不得不推迟,而甲方对此也表示理解并积极协商与配合。这是因为你在签订合同时,写上了()条款。

A.水土不服

B.员工患病

C.不可抗力

D.上帝意旨

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