用所给单词的适当形式填空.
1. We should give up those _______ (waste) habits in order to save our world.
2. The foreigners had an _______ (enjoy) time on the Great Wall yesterday.
3. I think __________(environment) education for kids is necessary.
4. Most students in our school often collect _______ (reuse) waste for recycling.
5. If we don't look after our earth well, the future will be _______ (hope).
