热门试题:
[单选题]认证的目的不包括()。
A.发送者是真的
B.接受者是真的
C.消息内容是真的
D.消息内容是完整的
[单项选择]女性，30岁，哮喘病史近10年，近2年来反复发作，午夜或清晨时易发，春季和梅雨季节尤其好发。查体：一般情况可，叙述病史连贯而无气急，两肺散在哮鸣音。患者近日发作频繁时，医生推荐加用β2受体激动剂，首选药物是（）
A. 肾上腺素
B. 去甲肾上腺素
C. 异丙肾上腺素
D. 沙丁胺醇（舒喘灵）
E. 麻黄素
[不定项选择题]共用题干
第一篇
How the First Stars in the Universe Came into Existence
Researchers believe that our universe began with the Big Bang（宇宙大爆炸）about 13 billion years
ago,and that soon after that event,matter began to form as small dust grains and gases.How the first stars
formed from this dust and gas has been a burning question for years,but a state-of-the-art computer simula-
tion now offers the most detailed picture yet of how these first stars in the universe came into existence.
The composition of the early universe was quite different from that of today,and the physics that
governed the early universe were also somewhat simpler. Dr. Naoki Yoshida and colleagues in Japan and the
U.S.incorporated these conditions of the early universe,sometimes referred to as the"cosmic dark ages",to
simulate the formation of an astronomical object that would eventually shine its light into this darkness.
The result is a detailed description of the formation of a protostar（原恒星）一the early stage of a mas-
sive primordial（原始的）star of our universe , and the researchers ' computer simulation , which has been
called a"cosmic Rosetta Stone"sets the bar for further investigation into the star formation process.The ques-
tion of how the first stars evolved is so important because their formations and eventual explosions provided
the seeds for subsequent stars to come into being.
According to their simulation,gravity acted on minute density variations in matter,gases,and the myste-
riou;"dark matter"of the universe after the Big Bang in order to form this early stage of a star一a protostar
with a mass of just one percent of our sun. The simulation reveals how pre-stellar（前恒星的）gases would
have actually evolved under the simpler physics of the early universe to form this protostar.
Dr. Yoshida's simulation also shows that the protostar would likely evolve into a massive star capable of
synthesizing（合成）heavy elements,not just in later generations of stars,but soon after the Big Bang.
"This general picture of star formation,and the ability to compare how stellar objects form in different
time periods and regions of the universe,will eventually allow investigation into the origins of life and
planets,"said Lars Herriquist,a professor of Astronomy at Harvard University and a co-author of this latest
report."The abundance of elements in the universe has increased as stars have accumulated,"he says,"and
the formation and destruction of stars continues to spread these elements further across the universe.So all of
the elements in our bOdies originally formed from nuclear reactions in the centers of stars,long ago."
Their simulation of the birth of a protostar in the early universe signifies a key step toward the ambitious
goal of piecing together the formation of an entire primordial star and of predicting the mass and properties of
these first stars of the universe.More powerful computers,more physical data,and an even larger range will
be needed for further calculations and simulations,but these researchers hope to eventually extend this simu-
lation to the point of nuclear reaction initiation一when a stellar object becomes a true star.
"Dr. Yoshida has taken the study of primordial star formation to a new level with this simulation,but it
still gets us only to the halfway point towards our final goal.It is like laying the foundation of a skyscraper,"
said Volker Bromm,assistant professor of Astronomy at the University of Texas, Austin and the author of a
companion article."We must continue our studies in this area to understand how the initially tiny protostar
grows,layer by layer,to eventually form a massive star. But here,the physics become much more complicated
and even more computational resources are needed."
According to Paragraph 4,which of the following is NOT true about a protostar?
A.It developed into a massive star during the Big Bang.
B.It evolved from pre-stellar gases.
C.It was able to integrate heavy elements when evolving into a massive star.
D.It had a mass of one percent of the sun.
[判断题]专责监护人临时离开工作现场时，应通知工作负责人停止工作，待专责监护人回来后方可恢复工作。
A.正确
B.错误
[单项选择]以下关于福特翼博轴距大小说法正确的是（）。
A. 2520mm
B. 2530mm
C. 2540mm
D. 2550mm
[判断题]229、路网监控管理主要业务包括新事件预警、事件录入、事件确认、事件撤销、事件查询。
A.正确
B.错误
[单选题]化学品泄漏事故发生时,下面( )做法是错误的。
A.报警
B.进行交通管制
C.所有人员参加事故救援
[单项选择]
Although a given waveform may contain frequencies over a very broad range, as a practical matter any transmission system will be able to accommodate only a limited band of (86) . This, in turn, limits the data rate that can be carried on the transmission (87) A square wave has an infinite number of frequency components and hence an infinite (88) However, the peak amplitude of the kth frequency component, kf, is only l/k, so most of the (89) in this waveform is in the first few frequency components. In general, any digital waveform will have (90) bandwidth. If we attempt to transmit this waveform as a signal over any medium, the transmission system will limit the bandwidth that can be transmitted.
（90）是（）
A. small
B. limited
C. infinite
D. finite
[单项选择]物质吸收红外光，一般产生（）光谱。
A. 振动B.转动
B. 振动一转动
C. 线状
[判断题]通信卫星按运行轨道分为低轨道卫星、静止轨道卫星两类。
A.正确
B.错误
[单选题]无缝线路地段,当预测施工轨温高于原锁定轨温( )以上时,线路清筛前必须进行应力放散,放散轨温应满足施工期间作业安全要求。
A.7℃
B.10℃
C.12℃
D.15℃
[简答题]
患者男性，55岁。主诉：咳嗽、咳痰1个月，加重伴痰中带血2周。
现病史：1个月前无明显诱因出现刺激性咳嗽、咳痰，起初为少量黏液痰，后咳大量脓痰，痰中带血2周，伴发热。无心悸、胸痛，无腹胀、腹泻等。在当地医院就诊，诊断为"肺炎"，治疗效果欠佳。为进一步诊治去某院。患者发病来，体重下降约3kg。既往有30年吸烟史，25支／天，否认疫区接触史，无药物过敏史。
体格检查：T36，8℃、P84次／分，R18次／分，BP120/85mmHg，发育正常，营养一般，神清合作，全身皮肤无黄染，双锁骨上窝未及肿大淋巴结，心（－），双肺呼吸音粗，右下肺呼吸音低，叩浊音。腹平软，无腹壁静脉曲张，全腹无压痛，肝、脾肋下未触及，听诊肠鸣音4次／分，肛门指诊未及异常。
辅助检查：Hb86g/L，WBC14.5×109／L，CT示：右下肺肺炎伴肺不张，右下肺支气管管腔狭窄，管壁有新生物向腔内凸起。
要求：根据以上病历摘要，请写出初步诊断、诊断依据（如有两个以上诊断，应分别写出各自诊断依据，未分别写出扣分）、鉴别诊断、进一步检查与治疗原则。
[单选题]制作爆菜的原料主要有家禽畜的内脏,干货原料和( )动物性原料。
A.猪肝
B.猪腰
C.猪肚
D.鲜嫩无骨
[判断题]运输、牵引供电、电务、工务、车辆、通信、公安等有关人员，凭登乘机车证可登乘机车。
A.正确
B.错误
[单选题]粗苯槽罐放散气汇集后输送至（）
A.鼓风机前煤气管
B.电捕前煤气管
C.鼓风机后煤气管
[判断题]大风天气，补强防溜措施的采取或撤除的具体分工、联系及防溜揭示等办法在《站（段）细》和《安全协议》中规定。
A.正确
B.错误
[判断题]绝缘接头最大轨缝不得大于构造轨缝。
A.正确
B.错误
[单项选择]异位妊娠的诊断，哪项最准确（）
A. 病史及盆腔检查
B. hCG
C. 后穹窿穿刺
D. 诊断性刮宫
E. B超
[判断题]根据《行政处罚法》规定,当事人承担行政机关组织听证的部分费用
A.正确
B.错误
[单选题]短接故障线路、设备前，应确认故障已（ ）。
A.A-消除
B.B-隔离
C.C-处理
D.D-屏蔽
[单项选择]男性，43岁。近3天来便后肛门出现一肿物，疼痛剧烈，排便、坐、走、咳嗽等均感疼痛而致坐卧不安。最可能的诊断是（）
A. 肛旁脓肿
B. 血栓性外痔
C. 直肠脱垂
D. 混合痔
E. 肛乳头脱出
[单项选择]某建设项目，承包人与分包人口头约定了施工合同内容，施工任务完成后，由于承包人欠工程款而发生纠纷，但双方一直没有签订书面合同，此时应认定( )。
A. 施工合同成立，但不生效
B. 施工合同成立，且已生效
C. 施工合同不成立，不生效
D. 施工合同不成立，但有效
[单选题]局管内旅客列车经（）批准，可不隔离。
A.铁路局长
B.总工室
C.运输部
D.机务部
[多项选择]高压交流电动机大修时，一般都需要进行试验项目有（）
A. 电动机定子绕组测量绝缘电阻和吸收比
B. 直流电阻
C. 直流耐压和泄漏电流
D. 交流耐压
[单选题]行包、货物损失赔偿通知书(以下简称“赔通”)下达后应及时送财务部门。财务部门接到“赔通”后，应在（ ）内支付赔款。
A.A、5个工作日
B.B、6个工作日
C.C、7个工作日
D.D、10个工作日
[单选题]各车站组织一次消防安全培训的周期为（ ）。
A.每月
B.每季度
C.每年
D.每半年
[单选题]( )仅在其主体信号机开放时点亮，用于区别进路开通方向或双线区段反方向发车，不能独立构成信号显示。
A.进路表示器
B.道岔表示器
C.调车表示器
D.脱轨表示器
[单项选择]男性，41岁。不规则发热4周余住院，最高体温41℃，最低37．5℃。在考虑病因时下列哪种疾病最不可能（）
A. 细菌性感染
B. 病毒性感染
C. 恶性淋巴瘤
D. 结缔组织病
E. 肉芽肿性疾病
[单项选择]治烧伤剂在使用中应注意的是（）。
A. 本类中成药为外用制剂，不可内服
B. 本类中成药大多性寒，易伤阳损脾，故脾胃虚寒者慎用
C. 本类中成药大多辛散苦燥，有伤阴耗血或损伤脾胃之弊，故阴虚血少或脾胃虚弱者慎用
D. 本类中成药均含有活血祛瘀药，故孕妇慎用
E. 本类中成药大多苦寒清泄，阴性疮疡脓水清稀、疮面凹陷者不宜应用
[单项选择]关于测量系统的线性研究，以下说法正确的是（）
A. 测量系统的线性指量具在量程的任何一处不存在偏倚
B. 测量系统的线性指其计量特性随时间保持恒定的能力
C. 测量系统的线性指其偏倚在量程范围内呈线性程度
D. 以上说法都不正确
[单选题] 等会列车时，不准关闭（），并应将头灯灯光减弱或熄灭。
A.柴油机
B.通风机
C.空气压缩机
[单项选择]下列选项中的 方法可以正确地加入类Child中，且父类的方法不会被覆盖。
public class Parent
public int addValue(int a,int b)
int s；
s=a+b；
return s；
class Child extends Parent
A. int addValue(int a,intb)∥do something…
B. public void addValue( )∥do something…
C. public int addValue(int a,intb)throws MyException∥do something…
D. public float addValue(int a,int b,float b=1.0)∥do something…
[不定项选择题]A.道德的主要功能
A.道德的本质
B.道德的特点
C.道德评价的标准
D.道德评价方式
E.用以调整人们之间及个人与社会之间的行为规范是( )
[单项选择]在网路保全的方式中，目前最常用的方式是（）
A. DNA验证
B. 生物特征辨识
C. 主机保全
D. 密码设定
