From Jonas' conversation with his parents in chapter 2, name three assignments that can be given at the Ceremony of Twelve. From The Giver

Nurturer, Doctor, Engineer

In the conversation with his parents, Jonas reveals his nerves about assignments. His parents assure him that the Elders pay attention to each child and determine the best assignment based on the person's strengths and attributes. His father talks about his two friends which were assigned as Doctor and Engineer. In one instance his friend was surprised and in the other it was what his friend had wanted all along. We also know that some people are assigned as Laborers and that is not something Jonas wants.