1. As we know, natural resources is a limited resource. If we keep wasting them, we won't have food, water, electricity to use in the future. In order to save energy, we can use household appliances economically. Besides, we should encourage people to be aware of saving energy. The government should have laws about it. Fine heavily people who break the law. What's more, we should use public transportation. If we can do that, we will save energy. Our earth will be saved and we can live healthily.

2. Many people believed that students have bad health because of smartphones. In my opinion, this has both advantages and disadvantages. One of the advantages is that they can make friends and relationships. They have relaxation after the hard work every day. Moreover, Internet helps them study online which is a convenient and effective way of learning. The disadvantage of this is that they can be addicted to games and social media.