热门试题:
[单项选择]单环芳烃的苯环结构是一个闭合的共轭体系，具有特殊的稳定性，因此易发生（）。
A. 氧化反应
B. 加成反应
C. 取代反应
D. 合成反应
[填空题]
Should We Ban Human Cloning or Not
The world was stunned by the news in the summer of 1995, when a British embryologist named Ian Wilmut, and his research team, successfully cloned Dolly the sheep using the technique of nuclear transfer. Replacing the DNA of one sheep’s egg with the DNA of another sheep’s the team created Dolly. Plants and lower forms of animal life have been successfully cloned for many years, but before Wilmut’s announcement, it had been thought by many to be unlikely that such a procedure could be performed on larger mammals and life forms. The world media was immediately filled with heated discussions about the ethical implications of cloning.
Some of the most powerful people in the world have felt compelled to act against this threat. President Clinton swiftly imposed a ban on federal funding for human-cloning research. Bills were put in the works in both houses of Congress to outlaw human cloning because it was deemed as a f
[单项选择]船员在船上发现火灾时应（）.
A. 立即救火
B. 切断通风
C. 大声呼唤报警
[单选题]党内政治生活的重要内容和载体是()。
A.批评与自我批评
B.党的组织生活
C.民主集中制
D.党内监督
[单选题]近日，有人称甲状腺癌在癌症中的发病率大幅升高，主要原因是长期食用加碘盐。而据专家介绍，世界卫生组织推荐成人每日碘摄入量为150-300微克，欧盟和美国的医学研究机构认为成人碘摄入可耐受上限每日600微克和1100微克。我国碘盐平均含碘量为30毫克／千克。按每人每日摄入盐5-10克计算，每日摄碘量约为150-300微克。扣除烹调和人体代谢的损失，碘摄入量不会高于世界卫生组织推荐量。这段文字意在说明的是：( )
A.食用碘盐易诱发甲状腺癌无根据
B.过量食用碘盐不利于身体健康
C.甲状腺癌发病与多种因素相关
D.我国居民碘摄入量符合安全标准
[单选题]安全通道顶棚平面的钢管做到设置两层（十字布设）、间距（）mm，钢管上竹笆或木工板铺设，上层四周应设置900mm高围栏、竹笆或木工板围挡；设有针对性的安全标志牌等。
A.400
B.600
C.800
D.100
[判断题]由车站担当取送车作业的货物线、段管线、专用线，未经汇报禁止调车作业。（ ）(《铁路调车作业补充规定》第25条)
A.正确
B.错误
[单项选择]引起机械性肠梗阻最常见的原因（）。
A. 肠腔堵塞
B. 肠管受压
C. 术后肠粘连
D. 肠壁狭窄
E. 肠壁肿瘤
[单选题]维生素B12缺乏症的血象呈
A.小细胞低色素性
B.小细胞高色素性
C.单纯小细胞性
D.大细胞正色素性
E.正常细胞性
[单选题]砂轮应进行定期检查。砂轮应无裂纹及其他不良情况。砂轮应装有用（）制成的防护罩，其强度应保证当砂轮碎裂时挡住碎块。防护罩至少要把砂轮的上半部罩住。
A.坚硬的木板
B.钢板
C.铝塑板材
D.环氧玻璃钢
[判断题]操作者用外卡钳在钢尺上量取尺寸时，应使一卡尖紧贴钢尺的端部不动，另一卡尖微微摆动，其最小值为量取的尺寸。
A.正确
B.错误
[判断题]坚持党要管党、全面从严治党,抓住“关键少数”、管好“绝大多数”,始终保持党的先进性和纯洁性。( )(《条例》第一章总则第四条第二项)
A.正确
B.错误
[不定项选择题]从全班60名学生中按学号随机抽取6名学生调查其上网情况。6名学生的上网时间（小时／周）分别是：16、12、5、5、10和18。
请根据上述资料从下列备选答案中选出正确答案。
可以采用()来反映学生上网时间的差异程度。
A.极差
B.众数
C.方差
D.标准差
[判断题]《钢轨探伤管理规则》规定，探伤生产机构应配备钢轨焊缝探伤试块，如GTS-1或等效的GHT-2、GHT-3、GHT-4试块。
A.正确
B.错误
[单选题]单活塞杆液压缸工作时，活塞要获得大的推力，油液对活塞腔的作用（ A ）对活塞杆腔的作用力。
A.大于
B.等于
C.小于
D.大于等于
[判断题]油气井井口距铁路、高速公路不小于50m。
A.正确
B.错误
[单项选择]Most propellers on merchant vessels are constructed of（）.
A. managanese bronze
B. cast iron
C. mild steel
D. improved plow steel
[判断题] ( )测量电压低于24 V的二次回路的绝缘电阻,只允许使用500 V的兆欧表测量。
A.正确
B.错误
[判断题]保证敞车下扇车门开度的一种支掌装置称为支门器。
A.正确
B.错误
[单项选择]冷空气侵入我国最多的路径是（）
A. 西路
B. 中路
C. 东路
D. 南路
[简答题]RGH20C道岔打磨车施工前有哪些准备工作?
[单选题]Je3A5319发电机长期运行时，处于定子绕组中靠近中性点的线圈绝缘比处于靠近出线端的线围绝缘老化速度( ).
A.快
B.慢
C.一样
D.没关系。
[多选题]绝缘手套使用前应进行（）检查。
A.A外观有无发粘、裂纹、破损、漏气
B.B合格标志
C.C在有效期内使用
D.
E.略
F.略
[单项选择]男，57岁。3月来腹胀、水肿，1周来加重伴腹痛。20年前曾发现HBsAg（+）。查体：可见肝掌及蜘蛛痣。蛙状腹，肝未及，脾肋下4cm，全腹压痛，无明显反跳痛，移动性浊音阳性。化验：血清蛋白24g/L，血球蛋白31g/L，血钾3.8mmol/L，血钠136mmol/L，血氯98mmol/L。该患者最必要的检查是（）
A. 腹水常规+细菌培养
B. 尿常规及尿钠检测
C. 腹部B超检查
D. 腹部CT检查
E. 胃镜检查
[单选题] “消防”一词是从( )传入我国的。
A.日本
B.英国
C.法国
D.美国
[填空题]污水处理厂在（）试运行基础上，应进行全厂性的联动试运行。
[单选题]皮肤病最常见的局部自觉症状是( )
A.疼痛
B.烧灼感
C.皮疹
D.麻木感
E.瘙痒
[填空题]旅客列车改为单管供风跨局运行时,由铁路总公司发布调度命令通知有关铁路局,按单管供风办理,直至( )。J342
[单选题]各种短路故障中，（ ）所占比例最高。
A.三相短路
B.两相短路
C.两相短路接地
D.单相接地短路
[单选题]杆上变压器及变压器台的安装,水平倾斜不大于台架根开的()
A.2/1000
B.3/1000
C.1/100
D.2/100
[单项选择]Hollywood has a message for scientists: If you want something that’s 100% accurate in every way, go watch a documentary. The thing is, when it comes to movies, narrative wins. The writer’s job is to get the characters right, not the science, says Tse, who cowrote Watchmen, one of last year’s most-anticipated superhero films. It annoys him, too, when things don’t make sense. He spent a lot of time and energy trying to find a fix for a logical problem in Watchmen--that one character, Dan, uses a completely obvious password to hack into the computer of Adrian, who is supremely intelligent. But for practical reasons, that kind of problem often just can’t be fixed. Maybe it would take too long, in an already long movie, or distract too much from the narrative, or cost too much to shoot.
Writers have faced similar problems with the TV show Heroes. The series follows a group of characters that have acquired superpowers: one is invisible, and one can walk through wall
A. get the science right in movies
B. invent a less obvious password
C. stay focused on the narrative
D. reduce the length of movies
[单项选择]X线胸片示有空洞形成，同侧或对侧肺野有斑片状或索条状阴影，常见于（）
A. 急性肺脓肿
B. 肺结核
C. 肺囊肿
D. 肺癌
E. 脓胸
[单选题]关于混凝土温度变形的叙述,不正确的是( )。
A.温度升高1°C,混凝土每米约膨胀0.01mm
B.普通混凝土的温度膨胀系数约为10×10-5/°
C.大体积混凝土浇筑时,内外温差不宜超过25°
D.掺入矿渣或减少水泥用量,可以有效减少混凝土温度变形
[单项选择]The student who wants a newspaper career has much hard work ahead of him before he can become even a cub, or beginning reporter. He may begin by working on his high school newspaper or yearbook.
Then the aspiring (有志的) reporter may break into newspaper work as a copyboy, running errands and helping sta. ff reporters. He may even be given a chance to write small stories. Sometimes students who are interested in news reporting can get jobs as campus reporters for local newspapers.
Jobs such as these serve to acquaint the beginner with the atmosphere of newsgathering. They give him a chance to sharpen his eye for details and teach him to be sure that his facts are accurate, that he reports them correctly, and that he writes his articles clearly. This work may lead to a job as a cub reporter on a newspaper, the important first step toward a career in news reporting.
The copyboy’s duties may sometimes include ______.
A. running errands for staff reporters
B. writing small news stories
C. reporting campus and student news
D. both A and B
[单选题]潮湿场所开关箱中的漏电保护器，其额定漏电动作电流为（ ）。
A.≥15mA
B.≤15mA
C.30mA
D.≤30mA
[多项选择]企业在进行租赁或购买设备决策时，需要考虑的主要因素包括( )。
A. 设备的保修方式
B. 货币的支付方式
C. 资金的筹集方式
D. 设备的使用成本
E. 设备的使用方式
