Although no one is certain why
migration occurs, there are several theories. One theory claims that prehistoric
birds of the Northern Hemisphere were forced south during the Ice Age. As the
glaciers melted, the birds came back to their homelands, spent the summer, and
then went south again as the ice advanced in winter. In time, the migration
became a habit in spite of the disappearance of glaciers. Another theory proposes that the ancestral home of all modern birds was the tropics. When the region became overpopulated, many species were crowded north. During the summer, there was plenty of food, but during the winter, scarcity forced them to return to the tropics. A more recent theory suggests a relationship between increasing daylight and the stimulation of certain glands(腺)in the birds’ bodies that may prepare them fo A. exact reasons for migration are not known B. birds migrate because of changes in temperature C. the ancestral home of all birds was the tropics D. glaciers caused birds to migrate [单项选择]该操作是由现场维护人员(包站人)来操作,具体到某一张工单,是由工单对应的()中配置的机房(动环)维护人员来接单,如果是多个维护人员,那么同时工单提醒,其中一个人接单后,其他人无需接单(系统自动不再显示),由接单人继续后续工单处理步骤
A. 站址信息 B. 物业信息 C. 工单信息 D. 区域信息 [单选题]A-C-G-024 4 2 3
跨越线路上部且有碍行车安全的施工,应( )防护。 A.办理封锁施工手续,设置移动停车信号 B.办理慢行手续,设置移动减速信号 C.办理临时封锁施工手续,设置停车手信号 D.设置作业标 [多选题]下列哪些是工业电雷管的主要性能参数( )。
A. 电阻 B. 最大安全电流 C. 最小发火电流 D. 重量 [多选题]以下属于押品评估虚假的表现情形包括()。
A.甲评估机构无资质或未经农业银行认可 B.乙评估机构出具的评估报告已过有效期 C.丙评估机构评估价值虚高 D.丁评估机构漏算土地出让金、应缴未缴税费、拖欠的建造费等款项 [简答题]何谓超载保护装置?
[多选题]公安机关职责具有“五性”特点:( )。
A.法律性 B.政治性 C.行政性 D.有限性 E.责任性 [单选题]导体的电阻取决于导体材料的( )、几何尺寸及导体的温度等。
A.物理性质 B.强调 C.化学性质 D.硬度 [单项选择]矿山瓦斯检测实际上是( )检测。
A. 甲烷 B. 乙炔 C. 二氧化碳 D. 硫化氢 [多项选择]证券公司违反《证券公司为期货公司提供中间介绍业务试行办法》规定的业务规则的,中国证监会及其派出机构可以采取以下()监管措施。
A. 责令限期整改 B. 监管谈话 C. 出具警示函 D. 责令期货公司终止与该证券公司的介绍业务关系 [简答题]根据《配电安规》,电话许可时工作许可人和工作负责人应分别记录许可时间和双方姓名,无须复诵核对无误。
[单选题]心悸气短与下列哪项同见,对诊断心阳虚证最有意义
A.面色萎黄 B.神疲乏力 C.形寒肢冷 D.头晕目眩 [判断题]城乡排涝中,利用市政工程设施排水,是应优先选用的排涝方法。
A.正确 B.错误 [单选题]防雷电感应接地干线与接地装置的连接不得少于2处,距离不得超过( )m。
A.12 B.16 C.24 D.32 [单项选择]能平调寒热,散结除痞的方剂是()
A. 半夏泻心汤 B. 大柴胡汤 C. 葛根黄芩黄连汤 D. 小柴胡汤 E. 逍遥散 [单选题]䅲.自律性最高的心肌组织是
A.A.窦房结 B.B.心房优势传导通路 C.C.房室交界 D.D.浦肯野纤细胞 E.E.房室束 [单选题]可燃物质在没有外部明火焰等火源的作用下,因受热或自身发热并蓄热所产生的自行燃烧现象,称为( )。
A.闪燃 B.自燃 C.爆燃 D.阴燃 [简答题]列车调度员接到车站(司机)发现有闲杂人员的报告后,应向尚未经过该地点的本线后续列车及邻线列车发布口头指示(或通过车站值班员转达)限速运行,旅客列车限速( ),旅客列车以外的列车限速60km/h。
[单项选择]以下哪项对风湿性心脏病主动脉瓣狭窄和先天性主动脉瓣狭窄鉴别诊断有帮助()
A. 20岁前发现胸骨右缘第二肋间有粗糙的收缩期杂音 B. 心电图示左室肥厚 C. X线示升主动脉扩张 D. 超声心动图示二叶主动脉瓣 E. 超声心动图示室间隔肥厚 [判断题]( ) 车辆运行中使用人力制动机时,必须使用安全带,要做到 "上车先挂钩"、"下车先摘钩"。( )
A.正确 B.错误 [单项选择]This is a famous street in China. What is it It’s West Street. Why is it so famous Now let me tell you something (41) it.
West Street is in Yangshuo, Guangxi. It’s over 1,400 years (42) .It’s about 1,000 meters (43) . But it’s very clean and beautiful. In the street, there are (44) shops. The things in the shops are nice and cheap. Every day, lots of visitors come here. Many of (45) are foreigners. It’s a good place to practice speaking English. So West Street is called the biggest English corner. Some people (46) call it the earth village. Almost everyone in the street (47) English. But you mustn’t ride your bike or drive your car in the West Street. You can only (48) here. Why Because it’s a walking street. In the street, you needn’t worry that you’ll be hit by cars. (49) happy! West Street is a wonderful place to visit. (50) West Street. A. old B. young C. big [单选题]下列电力网的构成说法正确的是()。
A.电厂-升压站-输电线路-降压站-配电线路-降压变压器-用户 B.电厂-升压站-输电线路-降压站-配电线路 C.电厂-升压站-配电线路-降压变压器-用户 D.电厂-升压站-输电线路-用户 [单选题]1.6 配调定位:配调是各单位地区调度管辖范围向配网的延伸,是公司加强配网运行管理和实施地县调控业务集约的( )。
A. A.政治保障 B.B.政治保证 C.C.组织保障 D.D.组织保证 [单选题]ZK4-170型电空转辙机电磁阀释放电压为( ).
A.≤DC1.5V B.≥DC1.5V C.≤DC2V D.≥DC2V [多选题]在用户设备上工作,许可工作前,工作负责人应检查确认用户设备的(____)符合作业的安全要求。
A.运行状态 B.安全措施 C.操作方法 D.使用说明 [单选题]()在日常维修、养护、巡检时,对管辖区段地面磁感应器的外观、设置地点须纳入检查范围,建立专项技术台账。
A.工务段 B.机务(动车)段 C.供电段 D.电务段 我来回答: 提交
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