ad hoc observers的用法和样例：
- The Committee unanimously decided to admit them to the meeting as ad hoc observers.
- Following discussions by the PCDA, it was decided that representatives of Yale Information Society Project and Knowledge Ecology International would attend the meetings of the PCDA as ad hoc observers.
- For example, at the SCCR, all NGOs that requested observer status were granted ad hoc observer status.
- Problems were solved on an ad hoc basis.
- Points of policy are decided ad hoc.