如图所示,实线表示在竖直平面内匀强电场的电场线,电场线与水平方向成α角,水平方向

题型:选择题

问题:

如图所示,实线表示在竖直平面内匀强电场的电场线,电场线与水平方向成α角,水平方向的匀强磁场与电场正交,有一带电液滴沿斜向上的虚线l做直线运动,l与水平方向成β角,且α>β,则下列说法中错误的是(  )

A.液滴一定做匀变速直线运动

B.液滴一定带正电

C.电场线方向一定斜向上

D.液滴一定做匀速直线运动

考点:带电粒子在复合场中的运动
题型:选择题

男性,57岁,既往体健,发热、咳嗽、咳黄脓痰3天,加重并气促1天入院。查体:体温39.5℃,呼吸32/分钟,脉搏112/分钟,血压88/56mmHg,神志清楚,精神萎靡,口唇发绀,右下肺闻及湿性啰音。胸片右下肺野见渗出病灶。初步诊断()

A.普通感冒

B.上呼吸道感染

C.重症社区获得性肺炎

D.下呼吸道感染

E.发热待查

题型:选择题

全口义齿排牙时,上颌第二前磨牙舌尖与平面的关系是()。

A.与平面相接触

B.离开平面0.5mm

C.离开平面1mm

D.离开平面1.5mm

E.离开平面2mm

题型:选择题

材料一:获得2008年度国家最高科学技术奖的中国科学院院士徐光宪坚持“立足基础研究,面向国家目标”的研究理念,将国家重大需求和学科发展前沿紧密结合,在稀土分离理论及其应用、稀土理论和配位化学、核燃料化学等方面做出了重要的科学贡献。他建立的“串级萃取理论”的广泛应用提升了我国在国际稀土分离科技和产业竞争中的地位,迫使国外稀土垄断企业纷纷减产和停产,被国际稀土界称为“中国冲击”,影响十分深远。 

材料二:“为了争取上大飞机项目,我们奋斗了20多年,如今中国人大飞机之梦终于要起飞了。”现年82岁、原国家科委科技干部局局长、大飞机专家金履忠教授激动地对记者表示。曾经担任国产ARJ21支线飞机副总设计师的周济生透露,大飞机制造零部件中最起码有50%以上需要对外招标。“这其中包括了飞机的发动机、大部分的机载设备和系统。”

看到上述材料,某校九年级1班的两个同学热烈的讨论起来。请你参与。

(1)郑尚勇同学不理解徐光宪院士的理论造成的“中国冲击”的关键及对我国的影响,你能吗? 

                                                                                                                                                             

                                                                                                                                                              (2)项开方同学觉得大飞机项目没有必要对外招标,你觉得呢? 

                                                                                                                                                             

                                                                                                                                                             

                                                                                                                                                             

题型:选择题

“Imagine you are walking along the road. Suddenly you fall over and all the passers-by burst into laughter. You feel very  1  and think the world is laughing at you . But in fact, five minutes later, they have  2   it ever happened.” The other day when I came across these words in an article, I didn’t agree with the  3  .
The author thinks the best thing to do in this kind of  4 is to pretend nothing has happened, and so avoid  5  trouble.
I admit that we should keep  6  because “Your tears will only remind others of what happened, while your  7  can let them forget it.” But this is far from satisfactory. We should do 8  to make things better.
I used to be a(n)  9  girl and not very good at maths. Our new maths teacher asked me a question and I still remember how I hung my head in  10  when I couldn’t answer it.
“If you don’t know the answer, just tell me.” the teacher said, “If you don’t how can I know   11  you know the answer or not?” All of my classmates burst into laughter. My face turned red but the teacher  12  me to go to the blackboard and  13  what I knew. If I had  14  the words in the article, I would have given up. But I tried my best. And to everyone’s  15 , I succeeded! The teacher smiled and said, “Well done! I  16  you could do it!”
Since then, I have become active in maths as  17  as in other subjects. I used to think doing maths exercises was a waste of time. But now, I know  18  I do can make things better. Everyone is the  19  of his own fate.
If we make mistakes, we should take on an active 20  . Laugh, and the world laughs with you; weep(哭泣), and you weep alone.
小题1:
A.nervousB.excited C.afraid D.embarrassed
小题2:
A.realizedB.recognized C.forgotten D.remembered
小题3:
A.speaker B.reader C.author D.announcer
小题4:
A.environmentB.surroundingC.condition D.situation
小题5:
A.ordinaryB.extra C.common D.usual
小题6:
A.confident B.smart C.calm D.strong
小题7:
A.smile B.worry C.courageD.satisfaction
小题8:
A.anything B.something C.nothingD.everything
小题9:
A.shy B.energeticC.happy D.clever
小题10:
A.joy B.prideC.shame D.surprise
小题11:
A.what B.that C.when D.whether
小题12:
A.forced B.invited C.asked D.pushed
小题13:
A.bring upB.put downC.think about D.show off
小题14:
A.obeyed B.doubted C.refused D.understood
小题15:
A.expectation B.disappointment C.surprise D.delight
小题16:
A.hoped B.knew C.doubtedD.regretted
小题17:
A.long B.far C.soon D.well
小题18:
A.whoever B.wheneverC.wherever D.whatever
小题19:
A.architect B.owner C.host D.controller
小题20:
A.position B.attitudeC.value D.response
题型:选择题

索引属于

A.模式

B.内模式

C.外模式

D.概念模式

更多题库