求翻译：这种情况下，应根据实际参评专家人数及其评价结果求平均，但专家人数不应低于总人数的一半，否则应无效。是什么意思？

In this case, the number of experts should be based on actual eligible, averaging the results of its evaluation, but the number of experts should not be less than half the total number of, or be invalid.

Under such circumstances, should be based on the actual number of experts' comments and their evaluation results for an average number of experts, but should not be less than half of the total number, otherwise, they should be invalid.

In this kind of situation, should act according to the actual senate to comment the expert population and the appraisal result asks the average, but the expert population should not be lower than the total number of people one half, otherwise should be invalid.

In this case, should be based on average actual prizes; number of experts and its evaluation results, but the number of experts should not be less than half of the total number, otherwise invalid.

In this case, should and its comment on the result to ask averagely according to the number of real expert participating in selecting, but expert's number should not be lower than half of the total number of person, otherwise should be invalid.