Your question is incomplete because you have not provided the underlined verb. However, the most likely verb underlined is the following:
My sister attend night school for the past five years and will graduate at the end of July.
Answer:
My sister has attended night school for the past five years and will graduate at the end of July.
Step-by-step explanation:
In the original sentence, the verb attend is in its infinitive base form. As a result, if the verb were in the present simple, its form would be attends, because the subject My sister is third person singular.
The reason why attend must be used in the present perfect is because the action started in the past and continues in the present. Thus, the speaker's sister is still attending night school and she has not finished yet.