not a teacher
1. We’ve held an old clothes recycling campaign at our school.
(Does it mean: The campaign is still going on.)
If you want to say that the campaign is still going on, it should be:
We have been holding an old clothes recycling campaign at our school.
2. The pollution in this city has become much worse. Hasn’t the Government done anything about?
(Does it mean: The pollution is continuing to get worse, and the Government is still not doing anything.)
The pollution is getting worse and the Government is not doing anything about it.