Sentence examples similar to two are obligatory from inspiring English sources

Six rotations are obligatory: cardiology, intensive care, pediatrics, anesthesiology, pre-hospital ambulance care and general practice.

Measures applied in Israel and in some of the ten countries are: obligatory helmet wearing, installing safety guardrails on roadsides.

Islam's Five Pillars are obligatory actions that Muslims must take.

Prayer should be a relaxing, enjoyable activity, but be aware that the five daily prayers are obligatory for all Muslims over the age of ten years.

She remembers spending up to three hours a day studying Arabic and the Quran, and would rarely miss the five daily prayers that are obligatory for Muslims.

Two years of military service are obligatory for men between the ages of 16 and 50 but voluntary for women.

These studies have identified two anionic amino acids, D126 and E172, that are obligatory for ligand binding.

An act that ought to be done is one that is obligatory for some agent, one that that agent ought to do, or that is his duty.

Goosebumps are obligatory.

Both are obligatory, of course.

At least one counselling interview between the pharmacist and the patient every three months was obligatory.