Rewrite the text from active into passive (use "by" if only

Rewrite the text from active into passive (use "by" if only necessary):

In autumn schoolchildren planted a lot of young trees in the area next to their school. They hope they will grow a fine park there in a few years. They have already мейд a plan of their park. Its winter now and they are protecting small trees from cold and wind. Their parents and teachers dont only give them advice, they also help them.