Fill in the blank with the correct verb tense structure: 'If I had known about the severe weather warning, I ___ to the coastal highway.'

Complete the sentence: If I had known about the meeting I ________ attended it.

If the camera was working, we _____ a movie.

If you _____ hard, you would not have failed in the exams.

If you work hard, you _____ good marks.

Complete the sentence with correct word inversion: 'Scarcely _______ compiled the revenue profiles when the federal structural adjustment policy was modified.'

Choose the grammatically precise option: 'The Commissioner mandated that every registered taxpayer _______ an integrated electronic invoicing system.'