Rewrite the text from active into passive (use "by" if only necessary): In autumn schoolchildren planted a lot of young

In autumn a lot of young trees were planted by schoolchildren in the area next to their school. They hope a fine park will be grown there in a few years. A plan of their park has already been made by them. It’s winter now and small trees are being protected by them from cold and wind. They are not only given advice by their parents and teachers, they are also helped by them.