Dưới đây là các từ phù hợp để điền vào các ô trống:

1. If beaches **are** clean, fewer people **will visit** them.
2. What **will happen** if we **do** nothing to reduce pollution?
3. If they **keep** throwing trash into the river, many fish **will die**.
4. We **will not reduce** wildlife if we **continue** air pollution.
5. If people **continue** to pollute the land, plants and trees **will die**.