ПОМОГИТЕ ПОЖАЛУЙСТА! 
1.(Have или Has) you watched the new film about Harry Potter?-Not yet.
2. Theere of the student (have или has) already finished the test.
3.Look at the players! I think they (have или has) never  played hockey.
4.They  (have или has) just arranged the date and time.
5.What  (have или has) happened to the boy?-i don't know.