3)idea
help
about
think
don't
work
thing
could
4)так и не поняла, письмо нужно писать или предложения, сделаю второе
Announcements should be placed to attract volunteers who would work on streets.
This and similar advertisements should be removed and new advertisements should be always checked on being true.
Local farm should be checked too, maybe animal protection organizations should be involved.
The school canteen is closing although it is quite important and convenient. All the students should be asked about their opinion and if the main part prefer the canteen to stay open then everyone should deal with the problem. For example, students can make a petition for the school administration.