1.   Nicole, the child whose mother died of AIDS, shuts down whenever the topic arises.

2.   The topic did not arise at a joint press conference with Bush and Musharraf last night.

3.   When the topic of war arises, however, the broad support for Israel betrays a certain shallowness.

4.   Though the medical staff and counselors do not focus on heart problems, the topic arises among the campers.