热门试题:
[判断题]对投切无功负荷的开关设备应实行差异化运维,缩短巡检和维护周期,每年统计投切次数并评估电气寿命。
A.正确
B.错误
[判断题]怀疑可能存在有害气体时,应立即将人员撤离现场,转移到通风良好处休息。抢救人员进入险区应戴防毒面具。
A.正确
B.错误
[单选题]依据《安全生产法》规定生产经营单位应当建立安全生产教育和培训档案,如实记录安全生产教育和培训的时间、内容、参加人员以及( )等情况。
A.授课人
B.培训学校
C.培训计划
D.考核结果
[判断题]建筑高度大于32米的住宅建筑应设置消防电梯。()
A.正确
B.错误
[多项选择]餐厅服务形式异彩纷呈,因根据客人需要提供对应服务,饭店餐厅常见的服务形式有()。
A. 共餐式
B. 分派式
C. 现场烹饪
D. 分餐式
[单选题] 在多人落水需要施救,应按“()”的顺序进行救援。( )
A. 先近后远,先水面后水下
B. 先远后近,先水面后水下
C. 先近后远,先水下后水面
D. 先远后近,先水下后水面
[判断题]水域救援中,绝不允许水域情况不明盲目下水救援。( )
A.正确
B.错误
[判断题]信号装置一般分为信号机和信号表示器两类。
A.正确
B.错误
[单选题]失去控制的船舶在锚泊后,应悬挂的号型是( )
A.垂直两个黑球
B.仅一个锚球
C.垂直两个黑球和一个锚球
D.两个锚球
[判断题]反接制动的优点是制动迅速。
A.正确
B.错误
[多选题]多项选择题:通常情况下选用电阻时需要考虑哪些指标( ) 。
A. 标称阻值
B. 允许偏差
C. 稳定性
D. 标称功率
[单选题]车站现阶段应执行的接发列车作业标准是总公司于( )发布的《接发列车作业标准》。
A.2009年2月12日
B.2007年2月12日
C.2009年6月12日
D.2007年4月12日
[单选题]有线调度通信系统有选呼、急呼、全呼、强插、强拆、监听、录音功能。调度工作台电话录音保存时间不少于( )个月。
A.3
B.6
C.9
D.12
[单选题]直流串励式起动机中的串励是指( )。
A.励磁绕组和电枢绕组串联
B.吸引线圈和电枢绕组串联
C.吸引线圈和保持线圈串联
[判断题]联动受托支付是指贷款资金发放后系统自动将贷款资金经贷转存账户直接划转至借款人交易对象银行结算账户的受托支付模式。
A.正确
B.错误
[单选题]停电线路、设备的断开点,应有能够反映线路、设备运行状态的电气和机械等指示。无明显断开点也无电气、机械等指示时,应断开()。
A. 同级电源
B. 下一级电源
C. 上一级电源
D. 断路器(开关)
[判断题]自动开车期间禁止进入安全护栏内,如需进入处理故障,请按下急停或从护栏门进入(护栏门与急停联锁,护栏门打开,现场急停)。
A.正确
B.错误
[单项选择]My new shirt cost me ______ the last one that I bought.
A. three
B. three times as much as
C. three times more than
D. as much three times as
[单选题]狭义的保险定义一般仅局限于( )的范畴。
A.人身保险
B.社会保险
C.商业保险
D.财产保险
[判断题]允许温升是由最高允许温度减去最高环境温度而得。
A.正确
B.错误
[单项选择]压磁测重传感器的信号线圈为()
A. 外侧
B. 篮绿色
C. 红白色
D. 黑白色
[判断题]( )27 列车是由两个连续的信标进行初始化定位。
A.正确
B.错误
[填空题]
A—Spring begins. B—the rains
C—insects awaken D—vernal equinox
E—clear and bright F—grain rain
G—Summer begins. H—grain buds
I—grain in ear J—summer solstice
K—slight heat L—great heat
M—Autumn begins. N—stopping the heat
O—white dews P—autumn equinox
Q—cold dews R—hoar-frost falls
S—Winter begins. T—light snow
U—heavy snow V—winter solstice
W—slight cold X—great cold
()立夏 ()大寒
[单选题]关于JPXC-1000继电器,以下说法不正确的是( )。
A.加反向200V电压时,衔铁不应吸起
B.线圈阻值为500Ω×2
C.偏极继电器
D.无极继电器
[判断题]弹条V型扣件调高垫板按厚度分为1mm、2mm、5mm和10mm四种规格,放置于轨下垫板与轨枕承轨面之间。
A.正确
B.错误
[单选题]在1区内电缆( )有中间接头,在2区、20区、21区内不应有中间接头。
A.必须
B.不得
C.可以
D.严禁
[不定项选择题]共用题干
Older Volcanic Eruptions
Volcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.
Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava(熔岩)that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.
The Permian(二叠纪)extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 10 gigatonnes of carbon as carbon dioxide.The global warming that followed wiped out 80 percent of all marine genera(种类)at the time,and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousand of years."The most recent ones hardly
have an effect at all,"Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid(小行星).He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2.
Vincent Courtill.ot,director of the Paris Geophysical Institute in France,says that Wignall's idea is provocative.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for tliousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions。
What is the main thesis of the article?
A.Volcanic eruptions are riot always deadly.
B.Older volcanic eruptions are more destructive.
C.Carbon dioxide emissions often give rise to global warming.
D.It is not easy to calculate the killing power of a volcanic eruption.
[多选题]《列车服务质量规范》中,备品柜或备品柜容量不足的,软卧车布制备品定位放置在( )号卧铺下。
A.3
B.5
C.7
D.11
[单项选择]钢材弯曲火焰矫正时,加热形状不采用()。
A. 四边形加热
B. 三角形加热
C. 线状加热
D. 点状加热
[单选题]《高速铁路无砟轨道线路维修规则》规定,高速道岔尖轨相对于基本轨降低值偏差超过( )mm且影响行车平稳性时,可通过更换不同厚度基本轨轨下橡胶垫板或滑床台,调整尖轨相对于基本轨降低值。
A.0.5
B.1
C.2
D.3
[多选题]以下哪些情况为耽误列车()?
A.列车在区间内停车
B.通过列车在站内停车
C.列车在始发站或停车站晚开
D.列车停运、合并、保留
[单选题]28、在建设工程项目施工前,承包人对难以控制的风险向保险公司投保,此行为属于风险应对措施中的( )。
A.A.风险规避
B.B.风险转移
C.C.风险减轻
D.D.风险保留