If an official from the government environmental protection department wants to speak at this non-governmental environmental protection seminar, he must be a member of a non-governmental environmental protection organization
However, the meeting stipulated that as a member of a non-governmental environmental protection organization, he is not allowed to be both an official of the government environmental protection department and a speaker at this non-governmental environmental protection seminar
Except for officials from the government's environmental protection department, no one spoke at this seminar