阅读下面材料，在空白处填入适当的内容或括号内单词的正确形式。
I can't help but feel ____(concern) about the ____(destroy) of tropical forests. It is one of the most serious environment problems today. From ____ I know, people are damaging thousands of square ____(kilometer) of forests every day. This is killing hundreds of wild animals that live in the forests.
____(fortunate), we do nothing but talk about it. We don't do anything ____(protect) the forests. We need to stop people doing it. There should be ____(strong) laws. I think that people who cut ____ forests should go to prison. That's what should happen to people who destroy the forests and kill wildlife.
In my opinion, we, human beings, must protect wildlife ____ future generations. Hopefully, our children ____(be) more responsible than we are today.
