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) ed ucation for kids is necessary. 4. Most students in our school often collect _______ (reuse) waste for recycling. 5. If we don't loo k after our earth well, the future will be _______ (hope).