●Big data can be described by four charaeteristics：volume、variety、locity and veracity。（71）refers to the quantity of generated and stored date.
●（72）is the extension of internet connectivity into physical devices and everyday objects.Embedded with electronics,internet connectivity,and other forms of hardware (such as sensors),these devices can communicate and interact with others over the internet,and they can be remotely monitored and controlled.
A. cloud computing
B. internet of things
C. biock chain
D. artificial intelligence
●（73）is a process of developing a document that formally authorizes the existence of a project and provides the project manager with the authority to apply organizational resources to project activities.
A.develop projece charter
B.manage project knowledge
C.monitor and control project work
D. close project
●（74）is a process of developing a detailed description of the project and product
A. collect requirements
B. definition scope
C. validate scope
●（75）is a process of monitoring the status of the project to update the project costs and manage changes to the cost baseline.