As 5G is widely deployed to provision network services for various vertical industrials, it becomes essential for mobile operators to design and optimize the deployment strategies of network slicing such that multiple vertical customers can be served concurrently with assured quality of services (QoS) whereas the operational cost efficiency is improved for mobile operators. One fundamental capability required is to create multiple network slices and associate them with vertical applications. The deployment strategies answer several key questions, such as: "How many network slice instances should be created to serve all subscribed vertical customers?"; "How these network slice instances should be isolated to assure the QoS and quality of experience (QoE) of these customers?"; "How the cost efficiency could be improved? e.g., via resource sharing, which, however, contradicts the isolation requirement". The answer to these questions decides the values created by network slicing to both mobile operators and vertical industries. Deploying the network slices and vertical applications according to the decided strategies imposes a series of challenges, particularly the unprecedent complexity in integration caused by the multi-vendor and multi-tenant deployment environment. Then enabling technologies are demanded to facilitate the practical deployment, e.g., automation, intelligence, integration, and open APIs. This presentation first revieWS- the requirements of deploying multiple network slices and services in 5G, followed by the current status of typical deployment decisions. Then challenges and open questions are overviewed for the future work.