质量1kg的物体放在水平地面上,一个大小为8N的水平恒力F作用在物体上2秒钟,使

题型:计算题

问题:

质量1kg的物体放在水平地面上,一个大小为8N的水平恒力F作用在物体上2秒钟,使物体从静止开始,沿直线运动4m,则(g=10m/s2)

(1)物体与地面间的动摩擦因数为多少?

(2)在接下来的1秒钟内,物体的位移是多少米?

考点:牛顿运动定律的应用
题型:计算题

中年男性,因腹胀不适2月余伴低热就诊。体检:神清,一般情况可,巩膜轻度黄染,肝肋下未及,脾肋下2指,肝功能A/G1.25,白蛋白30g/L。追问病史,10年前曾患乙肝,既往无呕血、黑便史,胃镜示食管胃底静脉曲张,B超示腹水(+)。

患者存在腹水,其形成原因不包括()。

A.门脉压力增高,组织液回流减少,漏入腹腔

B.淋巴输出不畅,从肝表面漏入腹腔

C.肝功能下降,白蛋白低导致血浆外渗

D.体内ADH增多导致水钠潴留

E.抗利尿激素分泌减少

题型:计算题

下列说法错误的是                                                   [ ]

A. 在研制治疗“甲型H1N1流感”药物过程中,化学起到了十分重要的作用

B. 利用化学可以研究和开发新能源

C. 利用化学可以合成许多自然界不存在的新物质

D. 为提高蛋白质含量,在牛奶中添加三聚氰胺

题型:计算题
One day I was doing a big clean­up when I ____ a knotted handkerchief with an old dark brown coin inside.I took one look and immediately ___ a forgettable time.
In 1991,I had spent five months in Niger,with sandstorms and great heat.Its ____ and beggars were my biggest and most constant complaint.Street beggars would continually reached out their hands,shouting “Gift!Gift!”
One day,I ___ for neighboring Burkina to work in a health clinic.
Arriving by taxi at our destination in Burkina,we began to ____.Out of the darkness,a motorbike with two men approached slowly.Without ____,one of the men grabbed my daypack as the motorbike swept close by.Within seconds,the two were out of sight,____ up by the night.
The bag had my passport,money,traveler’s cheques,camera,an airline ticket and other things ___ to me.I was in deep trouble.
In the weeks that followed,I ____guarded the rest of my valuables and regarded all ____ with suspicion.All I wanted was to leave this place.
Then,walking through Burkina’s streets,I met with an old woman.“Gift!Gift!” she cried.I’d had enough.I was ____ of the country:its poverty,its thieves,the heat,and the dust.I told her angrily,“A thief stole all my money and now I can’t ____ out of your country.I cannot give you anything.”
The beggar woman listened attentively and ___ my words.Then she reached ____ the folds of her dress.
“Then I will give you a gift,”she announced.Kindly,she placed an old,dark brown coin in my hand.I looked at it in ____.It was a very small amount of money  but for this woman,the coin ___ a meal.At that moment,I felt a shame.In spite of the ____,she was able to give me something priceless.
I saw then the ____ beauty of the people of Burkina—and appreciated deeply the quiet ____ of the poor.With the old woman’s gift,I hope never to part with the coin she gave me.With one small coin,she ____ my concept completely.
小题1:
A.cared aboutB.came across
C.looked forD.focused upon
小题2:
A.presentedB.gave
C.recalledD.reminded
小题3:
A.trafficB.dust
C.noiseD.climate
小题4:
A.headedB.made
C.stoodD.came
小题5:
A.moveB.unload
C.hideD.pass
小题6:
A.warning B.planning
C.thinkingD.arranging
小题7:
A.hungB.put
C.swallowed D.cleared
小题8:
A.obviousB.expensive
C.familiarD.precious
小题9:
A.elegantlyB.cautiously
C.dependently D.frequently
小题10:
A.localsB.thieves
C.beggarsD.motorbikes
小题11:
A.proudB.conscious
C.sickD.aware
小题12:
A.getB.run
C.comeD.rush
小题13:
A.attended toB.looked up
C.thought aboutD.wrote down
小题14:
A.forB.into
C.outD.at
小题15:
A.orderB.vain
C.caseD.shock
小题16:
A.meantB.made
C.servedD.suggested
小题17:
A.dirtinessB.poverty
C.kindnessD.safety
小题18:
A.updatedB.unfolded
C.brokenD.unexpected
小题19:
A.momentB.action
C.dignityD.life
小题20:
A.changedB.damaged
C.foundD.accepted
题型:计算题

玩具用电动机(输出功率为30W)的马达盖

题型:计算题

Bain回路是采用下列哪种系统回路的原理()。

A.Mapleson A回路

B.Mapleson B回路

C.Mapleson C回路

D.Mapleson D回路

E.Mapleson F回路

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