在一密闭容器中,有甲、乙、丙、丁四种物质,一定条件下充分反应,测得反应前后各物质

题型:选择题

问题:

在一密闭容器中,有甲、乙、丙、丁四种物质,一定条件下充分反应,测得反应前后各物质的质量如下表:

物质
反应前的质量20508030
反应后的质量010010x
请根据质量守恒定律判断x的值(  )

A.50

B.40

C.10

D.70

考点:质量守恒定律
题型:选择题

Back in the early 1900s, American physician Byron Robinson wrote a book proposing an interesting theory: humans actually have two brains --- one in our heads and the other in our stomachs, and the two “communicate” all the time. Interestingly, in Chinese culture, thoughts are also related to the belly in phrases and idioms like fugao (腹稿, a draft), manfu jinglun (满腹经纶, a bellyful of ideas), and yiduzi weiqu (一肚子委屈, a bellyful of complaints).

This may sound a little ridiculous at first. But try to think of a time when you were extremely nervous. Chances are that you also felt uncomfortable in your stomach, didn’t you? This is probably why people use the idiom “butterflies in one’s stomach” to refer to being nervous.

Now scientists from Canada and the US have found that our guts (肠道), if not as bright as our actual brains, are much more than just where we digest the food we eat. They also affect our emotions and even behavior, all thanks to the bacteria in them, reported Scientific American.

In the study, scientists fed timid mice stomach bacteria from mice that were more active and daring. After eating the bacteria, the timid mice grew more energetic and fearless. Sure enough, when bold mice got the bacteria from timid ones, they became more anxious. The mice’s behavior also changed when scientists disturbed the bacteria in their guts by changing their diets and feeding them antibiotics (抗生素).

“If something goes wrong in the gut, that change is reflected in the brain,” Emeran Mayer, a professor at University of California, Los Angeles, told The Huffington Post.

The brain-and-gut connection also works in the opposite way. Scientists studied children with autism (自闭症) --- a mental illness that makes people unable to socialize with others --- and found that they also have a lot of stomach problems. They have fewer types of stomach bacteria and lower totals of a few key bacteria than healthy children.

This research raises the possibility that scientists could treat patients with brain problems simply by feeding them the right food, which would be much more efficient than providing psychological therapy (疗法).

According to CBC News, you can get “good” bacteria that lift your spirits from food like yogurt while “bad” bacteria are usually in high fat and high sugar foods.

小题1:What is the author’s attitude toward Byron Robinson’s theory of two human brains?

A.Unsatisfied.

B.Doubtful.

C.Positive.

D.Negative.小题2:The author mentioned the idiom “butterflies in one’s stomach” in the second paragraph to _____.

A.describe the symptoms of nervousness

B.suggest a connection between our stomach and our emotions

C.hint at the danger of nervous feelings

D.encourage people to calm down and relax小题3:What’s the closest meaning of the underlined word “bold” in Paragraph 4?

A.anxious

B.fearless

C.energetic

D.sharp小题4:According to the article, ______.

A.people with mental illnesses are more likely to have stomach problems

B.the use of antibiotics can turn timid mice into daring ones

C.timid mice have fewer types of stomach bacteria than daring mice

D.people must consider changing their diets when they feel anxious小题5:We can infer from the article that______.

A.psychological therapy has never worked before for autistic children

B.yogurt is the best solution for anxiety problems

C.high fat and high sugar foods are responsible for many mental diseases

D.diet changes can lead to mood changes

题型:选择题

关,发展为中央官署之间相询庶务的平行公文的时期为()。

A.汉代

B.南北朝

C.唐宋

D.明清

题型:选择题

某基金总资产为50亿元,总负债为20亿元,发行在外的基金单位为30亿份,则该基金的基金单位净值为()元。

A.1

B.1.5

C.2

D.2.5

题型:选择题

关于先天性胆总管囊状扩张症描述不正确的是()。

A.囊肿无回声区上段与近端胆管不相通

B.又称先天性胆总管囊肿

C.呈椭圆形或梭形无回声区

D.胆囊常因囊肿向腹前壁推挤移位

E.胆囊大小多正常

题型:选择题

汽轮机扣大盖过程的最后部分,当汽缸一旦搁牢放不下时,可将大盖往上升,然后查找原因。

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