Надо ! указать модальные глаголы и их эквиваленты (залог,время) these documents should be treated as confidential payment is to be made against shipping documents packing should be suitable for transshipment in transit and reasonable long storage of the equipment

These documents should be treated as confidential (модальный глагол Present Simple Passive)
Payment is to be made against shipping documents (эквивалент модального глагола must. Present Simple Passive)
Packing should be suitable for transshipment in transit and reasonable long storage of the equipment (модальный глагол. Present Simple Active)