Final answer:
To complete the sentence, choose between 'aprobar' which means 'to pass,' or 'reprobar' which means 'to fail.'
Step-by-step explanation:
To complete the sentence, the best answer would be aprobar. This means 'to pass' or 'to approve.' So the complete sentence would be 'Tengo que estudiar mucho o voy a aprobar mi clase.' In English, this would translate to 'I have to study a lot or I'm going to pass my class.'
Another possible answer choice, reprobar, means 'to fail.' So if you choose this option, the sentence would mean 'I have to study a lot or I'm going to fail my class.'
Learn more about Completing a sentence in Spanish