Questions:
1. Why the writer was very sad?
2.Do you think the sign work?

A walk through the woods

I live in a very old town which is surrounded by beautiful woods. It is a famous beauty spot（点，地点） . On Sundays, hundreds of people come from the city to see our town and to walk through the woods. Visitors have been asked to keep the woods clean and tidy. Litter-baskets（废物筐） have been placed under the trees, but people still throw their rubbish（垃圾） everywhere. Last Wednesday, I went for a walk in the woods. What I saw made me very sad. I counted seven old cars and three old refrigerators（冰箱）. The litter-baskets were empty and the ground was covered with pieces of paper, cigarette-ends（烟头） , old tyres, empty bottles and rusty（生锈的） tins（白铁罐）. Among the rubbish I found a sign which said:” Anyone who leaves litter（废物，碎屑） in these woods will be prosecuted（指控，起诉） .”!