Answer for brainliest

allusion   is the right answer

no its not a run on sentence however i think you meant wet suits not sours also a run on sentence would be like surfers surf all winter long in southern california by using wet sours to keep them warm and the live their all year long  

there is 2 main differences, basically which are the users and the market. the other difference is the kind of content

people who use tik tok are mainly people from east asia, kind of like the app douyin. musically, on the other hand, are used by people from america or european countries.

while tik tok videos show things like daily life videos, comedy, or just funny videos, musically are like people mimicking songs with their own actions, 'imitate' singers and video clips.

hope this !