【单选题】
四格表资料的卡方检验时无需校正，应满足的条件是___
A. 总例数大于40
B. 理论数大于5
C. 实际数均大于1
D. 总例数大于40且理论数均大于或等于5
E. 总例数小于40
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相关试题
【单选题】
相对数使用时要注意以下几点，其中哪一项是不正确的___
A. 比较时应做假设检验
B. 离散程度和变异程度
C. 不要把构成比当率分析
D. 二者之间的可比性
E. 分母不宜过小
【单选题】
卡方检验适用于比较:___
A. 两个半差别的显著性
B. 多个率差别的显著性
C. 两个或多个构成比差别的显著性
D. 以上都可以
E. 以上都错
【单选题】
构成比的重要特点是各组成部分的百分比之和___
A. 一定大于1
B. 一定小于1
C. 一定等于1
D. 一定等于0
E. 随资料而异
【单选题】
卡方检验中自由度的计算公式是___
A. 行数×列数
B. n-1
C. N-k
D. (行数-1)×(列数-1)
E. 行数×列数-1
【单选题】
若X²≥X²0.05(v)则___
A. P≤0.05
B. P≥0. 05
C. P<0. 05
D. P=0. 05
E. P>0. 05
【单选题】
反映某一事件发生强度的指标应选用___
A. 构成比
B. 相对比
C. 绝对数
D. 率
E. 变异系数
【单选题】
均数与标准差之间的关系是:___
A. 标准差越大，均数代表性越大
B. 标准差越小，均数代表性越小
C. 均数越大，标准差越小
D. 均数越大，标准差越大
E. 标准差越小，均数代表性越大
【单选题】
铁路线路直线轨距标准为___ mm。J42
【单选题】
用于侧向接发停车旅客列车的单开道岔，不得小于___号。J46
【单选题】
侧向接发停车货物列车并位于正线的单开道岔，在中间站不得小于___号，在其他车站不得小于9号。J46
【单选题】
进站信号机在正常情况下的显示距离不得小于___。J69
A. 400 m
B. 800 m
C. 1 000 m
【单选题】
高柱出站、高柱进路信号机的显示距离，不得小于___。J69
A. 400 m
B. 800 m
C. 1000 m
【单选题】
不办理通过列车的到发线上的出站、发车进路信号机应采用___。J70
A. 矮型信号机
B. 高柱信号机
C. 通用信号机
【单选题】
进站信号机应设在距进站最外方道岔尖轨尖端（顺向为警冲标）不小于___的地点。J72
A. 50 m
B. 200 m
C. 400 m
【单选题】
出站信号机应设在每一发车线的警冲标___（对向道岔为尖轨尖端外方）适当地点。 J73
【单选题】
___信号机应设在闭塞分区或所间区间的分界处。J74
【单选题】
列车运行速度超过120 km/h的半自动闭塞或自动站间闭塞区段，设置两段接近区段，在第一接近区段和第二接近区段的分界处，设___。J76
A. 预告信号机
B. 接近信号机
C. 复示信号机
【单选题】
双线自动闭塞区段，有反方向运行条件时，出站信号机设___。 J78
A. 发车表示器
B. 进路表示器
C. 发车线路表示器
【单选题】
驼峰色灯辅助信号机，可兼作出站或___并根据需要装设进路表示器。 J84
【单选题】
集中联锁以外的脱轨器及引向安全线或避难线的道岔，设___。J86
A. 脱轨表示器
B. 进路表示器
C. 道岔表示器
【单选题】
在列车运行速度超过120 km/h的双线区段，采用速差式自动闭塞，列车紧急制动距离由___及以上闭塞分区长度保证。J94
【单选题】
LKJ设备应按高于线路允许速度___km/h常用制动设置模式曲线。J103
【单选题】
机车轮对踏面擦伤深度不得超过___ mm。J170
【单选题】
车轮踏面上的缺陷或剥离长度不超过40 mm，深度不超过___ mm。J170
【单选题】
接触网标称电压值为___kV，最高工作电压为27.5 kV，短时（5 min）最高工作电压为29 kV，最低工作电压为19 kV。J197
【单选题】
为保证人身安全，除专业人员执行有关规定外，其他人员（包括所携带的物件）与牵引供电设备带电部分的距离，不得小于___ mm。J205
【单选题】
在设有接触网的线路上，___攀登车顶及在车辆装载的货物之上作业；如确需作业时，须在指定的线路上，将接触网停电接地并采取安全防护措施后，方准进行。J205
A. 确认安全距离后可以
B. 严禁
C. 可以在有人监护下
【单选题】
在调度集中区段，调度集中控制车站有关行车工作由该区段___指挥。J227
A. 车站值班员
B. 列车调度员
C. 车站值班员和列车调度员共同
【单选题】
指挥列车运行的命令（运行揭示调度命令除外）和口头指示，只能由___发布。 J231
A. 车站值班员
B. 机车调度员
C. 列车调度员
【单选题】
双管供风的旅客列车运行途中改为单管供风时，列车调度员___。J231
A. 须发给司机调度命令
B. 给予司机口头指示
C. 通知车辆乘务员即可
【单选题】
驾驶机车的人员，必须持有___颁发的驾驶证。J243
【单选题】
编组超重列车时，在中间站应得到___的同意，并均须经列车调度员准许。J247
【单选题】
旅客列车列尾装置尾部主机的安装与摘解、风管及电源的连结与摘解，由___人员负责。J254
【单选题】
货物列车列尾装置尾部主机的安装与摘解，由___人员负责。J254
【单选题】
补机原则上应挂于本务机车的___，在特殊区段或需途中返回时，经铁路局批准，可挂于列车后部。J256
【单选题】
单机挂车的辆数，线路坡度不超过12‰的区段，以___辆为限；超过12‰的区段，由铁路局规定。J258
【单选题】
单机挂车在区间被迫停车后的防护工作由___负责，开车前应确认附挂辆数和制动主管贯通状态是否良好。J258
A. 机车乘务组
B. 车辆乘务员
C. 车站人员
【单选题】
机车、车辆长度的计算，以前后两钩舌内侧面距离按___m为换算单位（一辆）。 J259
【单选题】
特快及快速货物班列自动制动机主管压力为___ kPa。J261
【单选题】
遇机车换挂需将自动制动机列车主管压力由600 kPa改为500 kPa时，摘机前应对列车主管实施一次___kPa的最大减压量操纵。J261
推荐试题
【单选题】
In which scenario will vSphere DRS balance resources when set to Fully Automated?___
A. Hosts with only shared storage
B. Hosts are part of a vSphere HA cluster
C. Power Management is set to Balanced on hosts
D. Hosts with shared or non-shared storage
【单选题】
What VMware technology can be used to move physical servers to the vSphere infrastructure?___
A. VMware vMotion
B. VMware Converter
C. VMware vCenter Server
D. OVF transport
【单选题】
Upgrading vCenter Server with Microsoft SQL database fails with the following error message: The DB User entered does not have the required permissions needed to install and configure vCenter Server with the selected DB. Please correct the following error(s): %sWhat could cause this error?___
A. incorrect ports open on SQL Server
B. incorrect database on the SQL server
C. incorrect compatibility mode on the SQL server
D. incorrect permission on SQL Server database
【单选题】
What is a potential downside of having more than four paths per datastore?___
A. limits the storage protocols
B. increases storage latency for VM
C. limits the path selection policies
D. limits the number of LUNs per host
【单选题】
Which feature facilitates the sharing of templates via vCenter Server?___
A. Content Library
B. OVF
C. folders
D. vApp
【单选题】
A vSphere Administrator is in the process of configuring replication for a virtual machine, but is not able to select the Recovery Point Objective (RPO) value of 5 minutes. Which statement could explain why the RPO value cannot be lower than 15 minutes?___
A. The OS quiescing option is selected for Replication options.
B. The virtual machine hardware version is not compatible.
C. The target and source sites use different types of datastores.
D. The target and source sites are not using VMFS 6.0 datastore.
【单选题】
What advanced parameter defines a custom isolation IP address for a vSphere HA cluster?___
A. das.usedefaultisolationaddress
B. das.isolationshutdowntimeout
C. fdm.isolationpolicydelaysec
D. das.isolationaddress
【单选题】
Which method is supported for backing up the virtual machine that contains vCenter Server?___
A. differential
B. incremental
C. full image
D. individual disks
【单选题】
A vSphere Administrator must ensure that a user is able to view and manage the system configuration in vSphere Web Client. In the vCenter Single Sign-On domain, which group should the user be a part of?___
A. SystemConfiguration.BashShellAdministrators
B. ComponentManager. Administrators
C. Administrators
D. SystemConfiguration.Administrators
【单选题】
What is the minimum number of hosts that must contribute capacity to a non-ROBO single site VMware vSAN cluster?___
【单选题】
Which guest operating system supports PVRDMA?___
A. Windows (32-Bit)
B. Linux (32-Bit)
C. Windows (64-Bit)
D. Linux (64-Bit)
【单选题】
What is the correct way to replace the certificate on an existing vCenter Server that is part of a vCenter HA configuration?___
A. Put the vCenter HA in Maintenance mode, replace the certificate, exit Maintenance mode.
B. Shut down Passive and Witness nodes and replace the certificate on the Active node.
C. Remove the Passive and Witness nodes, replace the certificate, reconfigure the cluster.
D. Replace the certificate while all nodes are participating in the cluster.
【单选题】
The vSphere Data Protection performance analysis results in the “Conditionally Passed” status. What can cause this condition?___
A. The results did not meet the minimum performance expectations.
B. The read, write, and seek tests were successful.
C. The read and write tests were successful but the seek test failed.
D. The read and write tests were successful but the seek test skipped.
【单选题】
A vSphere Administrator wants to reserve 0.5 Gbps for virtual machines on each uplink on a disturbed switch that has 10 uplinks. What is the quota that should be reserved for the network resource pool?___
A. 10 Gbps
B. 5 Gbps
C. 100 Gbps
D. 0.5 Gbps
【单选题】
A vSphere administrator manages a cluster which includes critical and non-critical virtual machines. The cluster requires different permissions for contractors and non-contractors. How can the administrator exclude the contractor group from some of the critical VMs?___
A. Apply permission for both contractors and non-contractors on the cluster level.
B. Apply permission for both contractors and non-contractors on the cluster level. Remove permission on the critical VMs for contractors.
C. Remove permission for contractors on the cluster level. Apply permission on the critical VMs for noncontractors.
D. Apply permission for both contractors and non-contractors on the VMs. Remove permission on the critical VMs for contractors.
【单选题】
In an ESXi 6.5 cluster only "NFS datastore has running or registered virtual machines" returns. A vSphere HA cluster with four hosts has admission control configured to tolerate one host failure. Which statement is true if a fifth host is added?___
A. CPU and Memory capacity will be set to 50%.
B. CPU and Memory capacity will be set to 30%.
C. CPU and Memory capacity will be set to 25%.
D. CPU and Memory capacity will be set to 20%.
【单选题】
Which command can be run to troubleshoot connectivity problems with vmkernal network interfaces?___
A. esxcli network
B. vmkping
C. net-status
D. vicfg-vmknic
【单选题】
What counter should an administrator check to determine if a virtual machine is ballooning?___
A. swapinRate
B. vmmemctltarget
C. swapped
D. vmmemctl
【单选题】
By default, how often is the vCenter vpx user password automatically changed?___
A. 15 days
B. 60 days
C. 30 days
D. 45 days
【单选题】
Which metric in the Exhibit would identify high latency for a virtual machine operating system?___
A. QAVG/cmd
B. KAVG/cmd
C. DAVG/cmd
D. GAVG/cmd
【单选题】
What VM Monitoring setting would ensure that the failure interval for a virtual machine is defined as 120 seconds?___
A. High
B. Normal
C. Low
D. Medium
【单选题】
The business managers have asked the IT administrator to ensure configuration compliance in the vSphere infrastructure. The IT administrator wants to use Host Profiles to accomplish this, but is unable to do so. Why is the administrator unable to use Host Profiles?___
A. The infrastructure uses a vSphere Standard license.
B. The infrastructure has servers with various CPU families.
C. The user has only the “Administrator” role.
D. Host Profiles apply only to storage settings.
【单选题】
What is the result of a “Consolidate” action on a virtual machine?___
A. All snapshots on the virtual machines will be deleted.
B. The virtual machine will be reverted to its last snapshot.
C. Redundant delta disks will be combined and deleted.
D. A new snapshot with memory state will be created.
【单选题】
A Telco customer is implementing NFV using vSphere as the virtualization platform. Which feature can help achieve a high packet rate with lower CPU consumption?___
A. Network I/O Control
B. SplitRX
C. ERSPAN
D. LACP
【单选题】
What is the VMware-recommended best practice for Fibre Channel zoning?___
A. soft zoning
B. single-initiator-multiple-target zoning
C. single-initiator zoning
D. single-initiator-single-target zoning
【单选题】
How can a vSphere administrator ensure that a set of virtual machines run on different hosts in a DRS cluster?___
A. Use a VM-Host affinity rule.
B. Add the VMs to a vApp.
C. Use a VM-VM affinity rule.
D. Place the VMs in different folders.
【单选题】
vCenter Server Appliance Instance can be backed up using which Client Interface?___
A. vSphere Client Interface
B. vSphere Web Client Interface
C. VMware Host Client Interface
D. Virtual Appliance Management Interface
【单选题】
What tool can capture network traffic at the uplinks, or vSwitch, or virtual port levels?___
A. tcpdump-uw
B. wireshark
C. pktcap-uw
D. pcap
【单选题】
Which storage feature always requires the use of third-party software on ESXi?___
A. Hardware Acceleration for NAS devices
B. VVOL
C. Hardware Acceleration for Block
D. evices
【单选题】
An ESXi host's VMCA-Signed certificate has expired. How can the certificate be renewed?___
A. In the vSphere Web Client, browse to the host in question. Click the Manage tab and select settings. Select System and click Certificate, then click the Renew button.
B. In the vSphere Web Client, browse to the host in question. Click the Manage tab and select settings. Select System and click Certificate, then click the Refresh CA Certificates button.
C. Run the command /sbin/generate-certificates on the affected host.
D. Disconnect the host from vCenter Server and reconnect it.
【单选题】
Which is the correct order for upgrading vSphere components?___
A. vCenter Server, ESXi hosts, VMware Tools, Virtual Machine hardware
B. VMware Tools, Virtual Machine hardware, ESXi hosts, vCenter Server
C. vCenter Server, Virtual Machine hardware, VMware tools, ESXi hosts
D. ESXi hosts, vCenter Server, Virtual Machine hardware, VMware Tools
【单选题】
Which iSCSI initiator type can be used with any network interface card?___
A. Software iSCSI initiator
B. Software FCoE adapter
C. Hardware Independent iSCSI initiator
D. Hardware Dependent iSCSI initiator
【单选题】
An administrator is attempting to power on a virtual machine with 32GB of memory. The operation fails with the following error: <Could not power on VM: No space left on device> <Checking the space on the virtual machine's datastore, there is 30GB free.> Which action would allow the VM to power on?___
A. Set a 2GB memory reservation on the VM.
B. Mount the virtual disk from the affected VM on to another virtual machine and free up space from within the OS.
C. Enable vSphere HD admission control on the cluster in which the VM resides.
D. Set a 2GB memory limit on the VM.
【单选题】
An administrator attempts to manually reclaim space on thin-provisioned VMFS6 volumes but finds that no additional space is being recovered. Which could be causing this?___
A. vSphere 6.5 does not support manual UNMAP.
B. The manual UNMAP operation has been moved to the vSphere web client.
C. The VASA version is use is incompatible.
D. UNMAP is automated for VMFS6.
【单选题】
An administrator has upgraded to vSphere 6.5 and also wants to use Kerberos authentication for NFS. Which can be done to the existing NFSv3 volumes to enable this feature?___
A. Perform a storage rescan on VMFS volumes.
B. Unmount the NFSv3 datastore, and then mount as NFSv4.1 datastore.
C. Nothing. All NFSv3 mounted datastores are upgraded automatically during vSphere upgrades.
D. Perform a scan of new storage devices.
【单选题】
An administrator wants to restore the vCenter Server Appliance 6.5 from backup. Where can this be accomplished?___
A. from the ESXi Host Client
B. from the VMware vSphere Appliance Management Interface
C. from within the VMware vSphere Web Client
D. from the vCenter Server Appliance Installer
【单选题】
The administrator wants to power on VM-K2, which has a 2GHz CPU reservation. VM-M1, VM-M2, and VM-K1 are all powered on. VM-K2 is not powered on. The exhibit shows the parent and child resource reservations. If Resource Pool RP-KID is configured with an expandable reservation, which statement is true?___
A. VM-K2 will be unable to power on because there are insufficient resources.
B. VM-K2 will be able to power on since resource pool RP-KID has 2GHz available.
C. VM-K2 will be unable to power on because only 2GHz are reserved for RP-KID.
D. VM-K2 will receive resource priority and will be able to power on this scenario.
【单选题】
Which is the block size on the VMFS6 datastore?___
A. All small and large file blocks are 8MB.
B. All small and large file blocks are 1MB.
C. Small file blocks are 512KB. large file blocks are 64MB.
D. Small file blocks are 1MB, large file blocks are 512MB.
【单选题】
When installing vCenter Converter Standalone, why must an administrator perform a client-server installation instead of a local installation?___
A. to manage conversion tasks remotely
B. to convert virtual machines as well as physical machines
C. to allow installation of the Converter agent on remote source machines
D. to hot clone physical or virtual machines
【单选题】
Which is required by vCenter Converter Standalone to convert a physical Red Hat Enterprise Linux 7 machine to a virtual machine?___
A. The Linux machine must be powered off.
B. The Linux machine must have the SSH daemon started.
C. The Linux machine must use a static IP address.
D. The Linux machine must have a fully-qualified domain name.
